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Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most efficient therapeutic options available to cure many hematological malignancies. However, severe complications derived from this procedure, including graft-versus-host disease (GVHD) and infections, can limit its success and negatively impact survival. Previous studies have shown that alterations in the microbiome are associated with the development of allo-HSCT-derived complications. However, most studies relied on single techniques that can only analyze a unique aspect of the microbiome, which hinders our ability to understand how microbiome alterations drive allo-HSCT-associated diseases. Results: Here, we have applied multiple "omic" techniques (16S rRNA and shotgun sequencing, targeted and un-targeted metabolomics) in combination with machine learning approaches to define the most significant microbiome changes following allo-HSCT at multiple modalities (bacterial taxa, encoded functions, and derived metabolites). In addition, multivariate approaches were applied to study interactions among the various microbiome modalities (the interactome). Our results show that the microbiome of transplanted patients exhibits substantial changes in all studied modalities. These include depletion of beneficial microbes, mainly from the Clostridiales order, loss of their bacterial encoded functions required for the synthesis of key metabolites, and a reduction in metabolic end products such as short chain fatty acids (SCFAs). These changes were followed by an expansion of bacteria that frequently cause infections after allo-HSCT, including several Staphylococcus species, which benefit from the reduction of bacteriostatic SCFAs. Additionally, we found specific alterations in all microbiome modalities that distinguished those patients who subsequently developed GVHD, including depletion of anti-inflammatory commensals, protective reactive oxygen detoxifying enzymes, and immunoregulatory metabolites such as acetate or malonate. Moreover, extensive shifts in the homeostatic relationship between bacteria and their metabolic products (e.g., Faecalibacterium and butyrate) were detected mainly in patients who later developed GVHD. Conclusions: We have identified specific microbiome changes at different modalities (microbial taxa, their encoded genes, and synthetized metabolites) and at the interface between them (the interactome) that precede the development of complications associated with allo-HSCT. These identified microbial features provide novel targets for the design of microbiome-based strategies to prevent diseases associated with stem cell transplantation. Bx_7phuTozz8yFUTR9cZV4 Video Abstract [ABSTRACT FROM AUTHOR]

Introduction: The gut microbiota is believed to be directly involved in the etiology and development of chronic liver diseases. However, the holistic characterization of the gut bacteriome, mycobiome, and virome in patients with chronic hepatitis B-related liver fibrosis (CHB-LF) remains unclear. Methods: In this study, we analyzed the multi-kingdom gut microbiome (i.e., bacteriome, mycobiome, and virome) of 25 CHB-LF patients and 28 healthy individuals through whole-metagenome shotgun sequencing of their stool samples. Results: We found that the gut bacteriome, mycobiome, and virome of CHB-LF patients were fundamentally altered, characterized by a panel of 110 differentially abundant bacterial species, 16 differential fungal species, and 90 differential viruses. The representative CHB-LF-enriched bacteria included members of Blautia_A (e.g., B. wexlerae , B. massiliensis , and B. obeum), Dorea (e.g., D. longicatena and D. formicigenerans), Streptococcus , Erysipelatoclostridium , while some species of Bacteroides (e.g., B. finegoldii and B. thetaiotaomicron), Faecalibacterium (mainly F. prausnitzii), and Bacteroides_A (e.g., B. plebeius_A and B. coprophilus) were depleted in patients. Fungi such as Malassezia spp. (e.g., M. japonica and M. sympodialis), Candida spp. (e.g., C. parapsilosis), and Mucor circinelloides were more abundant in CHB-LF patients, while Mucor irregularis , Phialophora verrucosa , Hortaea werneckii, and Aspergillus fumigatus were decreases. The CHB-LF-enriched viruses contained 18 Siphoviridae , 12 Myoviridae , and 1 Podoviridae viruses, while the control-enriched viruses included 16 Siphoviridae , 9 Myoviridae , 2 Quimbyviridae , and 1 Podoviridae_crAss-like members. Moreover, we revealed that the CHB-LF-associated gut multi-kingdom signatures were tightly interconnected, suggesting that they may act together on the disease. Finally, we showed that the microbial signatures were effective in discriminating the patients from healthy controls, suggesting the potential of gut microbiota in the prediction of CHB-LF and related diseases. Discussion: In conclusion, our findings delineated the fecal bacteriome, mycobiome, and virome landscapes of the CHB-LF microbiota and provided biomarkers that will aid in future mechanistic and clinical intervention studies. [ABSTRACT FROM AUTHOR]

The fate of biobased and biodegradable cellulose-derived plastics in landfills represents an important topic from economic and environmental points of view. Anaerobic digestion is a cost-effective waste-to-energy technology. The behaviour of six polymer types—that is, cellulose (C), cellulose acetate (CA), viscose (V), nanocellulose (NC), acetate textile (AT), and heteropolysaccharide pectin (P)—was studied under anaerobic batch mesophilic conditions in a landfill leachate for 147 days. The cumulative biogas production was as follows: C>V=CA>>AT>>NC=P. Metagenomic analysis revealed notable variations in the proportion of bacterial and archaeal domains with the highest archaeal abundance in the presence of CA (80.2%) and C (78.5%). At the end of digestion, cellulolytic, hydrolytic, and dehydrogenase activities were measured in the intact samples, as well as the liquid and solid fractions, under aerobic and anaerobic conditions. Cellulolytic activity in P was detected only in the pellet, while in NC, activity was mostly in the supernatant under both aerobic and anaerobic conditions. Scanning electron microscopy and confocal scanning laser microscopy showed a defragmentation and degradation of polymeric substrates as well as microbial colonisation. Based on the results, landfill leachate is appropriate for the anaerobic biodegradation of cellulose-derived polymers; however, the process is polymer specific. [ABSTRACT FROM AUTHOR]

Aims: Metformin has been attributed to cardiovascular protection even in the absence of diabetes. Recent observations suggest that metformin influences the gut microbiome. We aimed to investigate the influence of metformin on the gut microbiota and hypertensive target organ damage in hypertensive rats. Methods: Male double transgenic rats overexpressing the human renin and angiotensinogen genes (dTGR), a model of angiotensin II‐dependent hypertension, were treated with metformin (300 mg/kg/day) or vehicle from 4 to 7 weeks of age. We assessed gut microbiome composition and function using shotgun metagenomic sequencing and measured blood pressure via radiotelemetry. Cardiac and renal organ damage and inflammation were evaluated by echocardiography, histology, and flow cytometry. Results: Metformin treatment increased the production of short‐chain fatty acids (SCFA) acetate and propionate in feces without altering microbial composition and diversity. It significantly reduced systolic and diastolic blood pressure and improved cardiac function, as measured by end‐diastolic volume, E/A, and stroke volume despite increased cardiac hypertrophy. Metformin reduced cardiac inflammation by lowering macrophage infiltration and shifting macrophage subpopulations towards a less inflammatory phenotype. The observed improvements in blood pressure, cardiac function, and inflammation correlated with fecal SCFA levels in dTGR. In vitro, acetate and propionate altered M1‐like gene expression in macrophages, reinforcing anti‐inflammatory effects. Metformin did not affect hypertensive renal damage or microvascular structure. Conclusion: Metformin modulated the gut microbiome, increased SCFA production, and ameliorated blood pressure and cardiac remodeling in dTGR. Our findings confirm the protective effects of metformin in the absence of diabetes, highlighting SCFA as a potential mediators. [ABSTRACT FROM AUTHOR]

Antarctic krill (Euphausia superba Dana) is a keystone species in the Southern Ocean ecosystem, with ecological and commercial significance. However, its vulnerability to climate change requires an urgent investigation of its adaptive potential to future environmental conditions. Historical museum collections of krill from the early 20th century represent an ideal opportunity to investigate how krill have changed over time due to predation, fishing and climate change. However, there is currently no cost‐effective method for implementing population scale collection genomics for krill given its genome size (48 Gbp). Here, we assessed the utility of two inexpensive methods for population genetics using historical krill samples, specifically low‐coverage shotgun sequencing (i.e. 'genome‐skimming') and exome capture. Two full‐length transcriptomes were generated and used to identify 166 putative gene targets for exome capture bait design. A total of 20 historical krill samples were sequenced using shotgun and exome capture. Mitochondrial and nuclear ribosomal sequences were assembled from both low‐coverage shotgun and off‐target of exome capture data demonstrating that endogenous DNA sequences could be assembled from historical collections. Although, mitochondrial and ribosomal sequences are variable across individuals from different populations, phylogenetic analysis does not identify any population structure. We find exome capture provides approximately 4500‐fold enrichment of sequencing targeted genes, suggesting this approach can generate the sequencing depth required to call identify a significant number of variants. Unlocking historical collections for genomic analyses using exome capture, will provide valuable insights into past and present biodiversity, resilience and adaptability of krill populations to climate change. [ABSTRACT FROM AUTHOR]

Objective: Metabolic and bariatric surgery (MBS) is associated with substantial, but variable, weight outcomes. The gut microbiome may be a factor in determining weight trajectory, but examination has been limited by a lack of longitudinal studies with robust microbiome sequencing. This study aimed to describe changes in the microbiome and associations with weight outcomes more than 2 years post surgery. Methods: Data were collected at two Midwestern U.S. centers. Adults undergoing primary MBS were assessed before and 1, 6, 12, 18, and 24 months after surgery. BMI and metagenomic sequencing occurred at each assessment. A linear growth mixture model determined class structure for weight trajectory. Results: A linear growth mixture model of participants (N = 124) revealed a two‐class structure; one class had greater sustained weight loss relative to the other. Greater genus‐level taxonomic changes in the microbiome composition at each time point were associated with being in the more favorable weight trajectory class, after controlling for surgery type. Higher Proteobacteria relative abundance at 1 month was predictive of percentage weight change at 6, 12, 18, and 24 months (p < 0.05 for all). Conclusions: Greater genus‐level taxonomic changes in the gut microbiota are associated with improved weight trajectory. Early changes in the gut microbiota may be an important indicator of MBS outcomes and durability. [ABSTRACT FROM AUTHOR]

This article discusses a study on the salivary microbiome in patients with periodontitis. The study found that patients with periodontitis had a higher abundance of certain bacteria in their saliva compared to the control group. Specifically, the study identified Fretibacterium species as a potential biomarker for periodontitis screening. However, further research is needed to fully understand the diagnostic and therapeutic implications of these findings. [Extracted from the article]

This study aimed to comprehensively characterize the gut microbiota in diarrheal mink. We conducted Shotgun metagenomic sequencing on samples from five groups of diarrheal mink and five groups of healthy mink. The microbiota α-diversity and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology did not show significant differences between the groups. However, significant differences were observed in microbiota β-diversity and the function of carbohydrate-active enzymes (CAZymes) between diarrheal and healthy mink. Specifically, The relative abundance of Firmicutes was lower, whereas that of Bacteroidetes was higher in diarrheal mink. Fusobacteria were enriched as invasive bacteria in the gut of diarrheal mink compared with healthy mink. In addition, Escherichia albertii was identified as a new bacterium in diarrheal mink. Regarding functions, nicotinate and nicotinamide metabolism and glycoside hydrolases 2 (GH2) family were the enhanced KEGG orthology and CAZymes in diarrheal mink. Furthermore, the diversity and number of antibiotic-resistant genes were significantly higher in the diarrheal mink group than in the healthy group. These findings enhance our understanding of the gut microbiota of adult mink and may lead to new approaches to the diagnosis and treatment of mink diarrhea. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a complex neurodegenerative disorder significantly impairing cognitive faculties, memory, and physical abilities. To characterize the modulation of the gut microbiota in an in vivo AD model, we performed shotgun metagenomics sequencing on 3xTgAD mice at key time points (i.e., 2, 6, and 12 months) of AD progression. Fecal samples from both 3xTgAD and wild-type mice were collected, DNA extracted, and sequenced. Quantitative taxon abundance assessment using MetaPhlAn 4 ensured precise microbial community representation. The analysis focused on species-level genome bins (SGBs) including both known and unknown SGBs (kSGBs and uSGBs, respectively) and also comprised higher taxonomic categories such as family-level genome bins (FGBs), class-level genome bins (CGBs), and order-level genome bins (OGBs). Our bioinformatic results pinpointed the presence of extensive gut microbial diversity in AD mice and showed that the largest proportion of AD- and aging-associated microbiome changes in 3xTgAD mice concern SGBs that belong to the Bacteroidota and Firmicutes phyla, along with a large set of uncharacterized SGBs. Our findings emphasize the need for further advanced bioinformatic studies for accurate classification and functional analysis of these elusive microbial species in relation to their potential bridging role in the gut-brain axis and AD pathogenesis. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Fecal microbiota transplantation (FMT) is a novel treatment for inflammatory diseases. Herein, we assess its safety, efficacy, and immunological impact in patients with moderate‐to‐severe atopic dermatitis (AD).In this randomized, double‐blind, placebo‐controlled clinical trial, we performed the efficacy and safety assessment of FMT for moderate‐to‐severe adult patients with AD. All patients received FMT or placebo once a week for 3 weeks, in addition to their standard background treatments. Patients underwent disease severity assessments at weeks 0, 1, 2, 4, 8, 12, and 16, and blood and fecal samples were collected for immunologic analysis and metagenomic shotgun sequencing, respectively. Safety was monitored throughout the trial.Improvements in eczema area and severity index (EASI) scores and percentage of patients achieving EASI 50 (50% reduction in EASI score) were greater in patients treated with FMT than in placebo‐treated patients. No serious adverse reactions occurred during the trial. FMT treatment decreased the Th2 and Th17 cell proportions among the peripheral blood mononuclear cells, and the levels of TNF‐α, and total IgE in serum. By contrast, the expression levels of IL‐12p70 and perforin on NK cells were increased. Moreover, FMT altered the abundance of species and functional pathways of the gut microbiota in the patients, especially the abundance of Megamonas funiformis and the pathway for 1,4‐dihydroxy‐6‐naphthoate biosynthesis II.FMT was a safe and effective therapy in moderate‐to‐severe adult patients with AD; the treatment changed the gut microbiota compositions and functions. [ABSTRACT FROM AUTHOR]

Central European forests have been shaped by complex human interactions throughout the Holocene, with significant changes following the introduction of domesticated animals in the Neolithic (∼7.5–6.0 ka before present [BP]). However, understanding early pastoral practices and their impact on forests is limited by methods for detecting animal movement across past landscapes. Here, we examine ancient sedimentary DNA (seda DNA) preserved at the Velký Mamuťák rock shelter in northern Bohemia (Czech Republic), which has been a forested enclave since the early Holocene. We find that domesticated animals, their associated microbiomes, and plants potentially gathered for fodder have clear representation by the Late Neolithic, around 6.0 ka BP, and persist throughout the Bronze Age into recent times. We identify a change in dominant grazing species from sheep to pigs in the Bronze Age (∼4.1–3.0 ka BP) and interpret the impact this had in the mid-Holocene retrogressions that still define the structure of Central European forests today. This study highlights the ability of ancient metagenomics to bridge archaeological and paleoecological methods and provide an enhanced perspective on the roots of the "Anthropocene." • We analyze metagenomic data from a rock shelter using sedimentary ancient DNA • Ancient DNA reveals domesticated animals and their associated microbiomes • Phylogenetic analyses detect mitochondrial haplogroups in domestic sheep and cattle • seda DNA can help improve the understanding of our herding practices and forest management Sedimentary ancient DNA buried underneath a rock shelter reveals shifts in the presence of domesticated animals, associated microbiomes, and plants gathered for fodder from the Late Neolithic to the Bronze Age. Zampirolo et al. highlight the potential of using ancient DNA from rock shelter deposits to infer past human-environment interactions. [ABSTRACT FROM AUTHOR]

Introduction: Pathogen introduction and transmission at the farm, regional, or national level are associated with reduced animal welfare and negative impacts on herd economics. Ongoing infectious disease surveillance, active or passive, is therefore of high importance. For optimal resolution, each pig is sampled individually, for example by collecting blood or nasal swabs. In recent years, oral fluids have become very useful for population surveillance at the pen level. Another alternative is sampling the air to capture pathogens circulating across the entire barn via bioaerosols. Objective: This study aimed to examine the potential utility of bioaerosol metagenomics for pathogen detection on pig farms. Methods: Bioaerosols via automated air sampler, and oral fluid via pen-based ropes, were collected from each of two Scottish indoor pig farms. All samples were subjected to conventional routine bacterial isolation. Total genomic nucleic acids were extracted for PCR screening for three pig DNA viruses, three bacterial Mycoplasma species and an RNA virus. Illumina shotgun metagenomic sequencing was also conducted. Results: Oral fluids contained more DNA compared to bioaerosol samples. DNA integrity exhibited limited impact on PCR or sequence yield. While Streptococcus suis could be cultured from a single oral fluid sample, reads mapped to S. suis were detectable in all metagenomic samples. Other bacterial pig pathogens, including Mycoplasma hyorhinis, M. hyopneumoniae and M. hyosynoviae, were detected in oral fluid and aerosols by PCR and metagenomics. One of the two farms was PRRSV positive, and the virus was detectable via PCR in oral fluids but not in bioaerosols. Antimicrobial resistance (AMR) gene profiles had less variation between bioaerosols and oral fluids. Some identified AMR genes had strikingly similar abundance overall. Conclusion: Overall, these findings indicate that there is potential utility of bioaerosol metagenomics for pathogen surveillance on pig farms; however, more research is needed for technical and cost optimization to allow for routine pathogen detection on livestock farms. [ABSTRACT FROM AUTHOR]

Background: Alterations in upper respiratory microbiomes have been implicated in shaping host health trajectories, including by limiting mucosal pathogen colonization. However, limited comparative studies of respiratory microbiome development and functioning across age groups have been performed. Herein, we perform shotgun metagenomic sequencing paired with pathogen inhibition assays to elucidate differences in nasal and oral microbiome composition and intermicrobial interactions across healthy 24-month-old infant (n = 229) and adult (n = 100) populations. Results: We find that beta diversity of nasal and oral microbiomes varies with age, with nasal microbiomes showing greater population-level variation compared to oral microbiomes. Infant microbiome alpha diversity was significantly lower across nasal samples and higher in oral samples, relative to adults. Accordingly, we demonstrate significant differences in genus- and species-level composition of microbiomes between sites and age groups. Antimicrobial resistome patterns likewise varied across body sites, with oral microbiomes showing higher resistance gene abundance compared to nasal microbiomes. Biosynthetic gene clusters encoding specialized metabolite production were found in higher abundance across infant oral microbiomes, relative to adults. Investigation of pathogen inhibition revealed greater inhibition of gram-negative and gram-positive bacteria by oral commensals, while nasal isolates had higher antifungal activity. Conclusions: In summary, we identify significant differences in the microbial communities inhabiting nasal and oral cavities of healthy infants relative to adults. These findings inform our understanding of the interactions impacting respiratory microbiome composition and functions related to colonization resistance, with important implications for host health across the lifespan. 5XcHcd9N21H4_6hqSTf5-o Video Abstract [ABSTRACT FROM AUTHOR]

Individuals with pancreatic-related health conditions usually show lower diversity and different composition of bacterial and viral species between the gut and oral microbiomes compared to healthy individuals. We performed a thorough microbiome analysis, using deep shotgun sequencing of stool and saliva samples obtained from patients with chronic pancreatitis (CP), pancreatic ductal adenocarcinoma (PDAC), and healthy controls (HCs).We observed similar microbiota composition at the species level in both the gut and oral samples in PDAC patients compared to HCs, among which the most distinctive finding was that the abundance of oral-originated Fusobacterium nucleatum species did not differ between the oral and the gut samples. Moreover, comparing PDAC patients with HCs, Klebsiella oxytoca was significantly more abundant in the stool samples of PDAC patients, while Streptococcus spp. showed higher abundance in both the oral and stool samples of PDAC patients. Finally, the most important finding was the distinctive gut phage–bacterial interactome pattern among PDAC patients. CrAssphages, particularly Blohavirus, showed mutual exclusion with K. oxytoca species, while Burzaovirus showed co-occurrence with Enterobacteriaceae spp., which have been shown to be capable of inducing DNA damage in human pancreatic cells ex vivo. The interactome findings warrant further mechanistic studies, as our findings may provide new insights into developing microbiota-based diagnostic and therapeutic methods for pancreatic diseases. [ABSTRACT FROM AUTHOR]

Background: Schizophrenia is a complex neuropsychiatric disorder with various etiologic factors. Aberrant levels of neurotransmitters or growth factors such as dopamine, serotonin, and BDNF have been shown to cause cognitive impairment in schizophrenia. Recently, the gut microbiome has also been suggested as a factor in the development of the disorder. To explore this potential link, we conducted a pilot study to examine the relationship between the gut microbiome and plasma levels of neurotransmitters and growth factors in schizophrenia. Shotgun metagenome sequencing of total RNA from fecal samples were used to profile the gut microbiome of schizophrenia patients (SCZ) and healthy controls (HC). The MetaPhlAn2 and HUMaN2 pipelines were used for bioinformatic analyses. ELISA was used to measure the plasma levels of dopamine, serotonin, and BDNF. Spearman's rank correlation coefficient was used for correlation analysis. Results: We found that butyrate-producing bacteria were enriched in HC, whereas succinate-producing bacteria, namely Phascolarctobacterium succinatutens and Paraprevotella clara, were enriched in SCZ. The gut microbiota of SCZ was enriched in lipid biosynthesis pathways related to bile-resistant bacteria, whereas phospholipid pathways linked with butyrate-producing bacteria were enriched in HC. Alistipes indistinctus, Dorea longicatena, and Roseburia inulinivorans were negatively correlated with dopamine levels. Roseburia intestinalis and Parabacteroides goldsteini were negatively correlated with serotonin and BDNF levels, respectively. We found a significant correlation between dopamine and serotonin levels, and the super-pathway of purine deoxyribonucleoside degradation. Conclusions: This study provides further support that gut microbiota could modulate neurotransmitter levels. The results suggest that gut microbiome-targeted therapies may help to rebalance neurotransmitter levels, offering new hope for the treatment of schizophrenia. [ABSTRACT FROM AUTHOR]

Water hyacinth (WH) is a widespread floating invasive aquatic plant with a prolific reproductive and dispersion rate. With the aid of its root-associated microbes, WH significantly modulates the ecosystem's functioning. Despite their irrevocable importance, the WH microbiome remains unexplored in detail. Here, we present a shotgun sequencing analysis of WH rhizobiome predominant in urban rivers and their surrounding water to unveil the diversity drivers and functional relationship. The core microbiome of the WH mainly consisted of the methane-metabolizing archaebacteria and sulfate-reducing bacteria, which are probably driving the methane and sulfur metabolic flux along the vegetative zone in the water. The beta diversity analysis revealed temporal variations (River WH_2020 vs. WH_2022) (R of 0.8 to 1 and R2 of 0.17 to 0.41), which probably could be attributed to the transient taxa as there was a higher sharing of core bacteria (48%). Also, the WH microbiome significantly differed (R = 0.46 to 1.0 and R2 of 0.18 to 0.52) from its surrounding water. Further, the functional analysis predicted 140 pollutant-degrading enzymes (PDEs) well-implicated in various xenobiotic pollutant degradation, including hydrocarbons, plastics, and aromatic dyes. These PDEs were mapped to bacterial genera such as Hydrogenophaga, Ideonella, Rubrivivax, Dechloromonas, and Thauera, which are well-reported for facilitating the metabolism of xenobiotic compounds. The higher prevalence of metal and biocide resistance genes further highlighted the persistence of resistant microbes assisting WH in bioremediation applications. [ABSTRACT FROM AUTHOR]

Atopic dermatitis is the most common inflammatory skin condition with a severe negative impact on patients' quality of life. The etiology of AD is complex and depends on age, genetics, the immune system, environmental factors, and the skin microbiome, with a key role for pathogenic Staphylococcus aureus in the development of severe AD. However, the composition of the skin microbiome in mild AD is understudied. Here, using metagenomic shallow shotgun sequencing, we showed that mild AD lesions did not show a significant difference in the diversity of the skin microbiome compared to samples from non-AD patients and that the relative abundance of S. aureus did not differ in these mild AD lesions. However, when we assessed other taxa, Mycobacterium ostraviense, Pedobacter panaciterrae_A and four Streptomyces species were identified with higher abundances in mild AD lesions and species of 15 genera were decreased in abundance. The highest fold decreases were observed for Paracoccus marcusii, Microbacterium lacticum, Micrococcus luteus, and Moraxella sp002478835. These microbiome compositional insights are a first step towards novel microbiome-based diagnostics and therapeutics for early intervention at the stage of mild AD and provide a path forward for the functional study of species involved in this often-overlooked patient population. [ABSTRACT FROM AUTHOR]

Lichen-feeding termites occupy a distinctive ecological niche. This feeding behavior underscores a complex interplay between the termites' digestive abilities and the biochemical properties of lichens, known for their resilience and production of secondary metabolites. Understanding the dietary preferences and digestive mechanisms of these termites offers insights into their ecological roles and the evolutionary adaptations that enable them to exploit such a specialized food source. We conducted experiments with Constrictotermes cyphergaster, feeding it with different combinations of its natural food sources: wood bark and lichen from host trees. Gut microbial communities were analyzed through 16S rRNA sequencing and shotgun metagenomics. Our results revealed that a diet containing lichens induces a shift in microbiota composition and increases the abundance of genes encoding an AA3 enzyme with a role in lignin digestion. This study emphasizes the potential role of lichens in enhancing the digestive capabilities of termites, highlighting the intricate relationships between diet, gut microbiota, and enzymatic activity in Termitidae. [ABSTRACT FROM AUTHOR]

Objectives Klebsiella pneumoniae is a significant pathogen with increasing resistance and high mortality rates. Conventional antibiotic susceptibility testing methods are time-consuming. Next-generation sequencing has shown promise for predicting antimicrobial resistance (AMR). This study aims to develop prediction models using whole-genome sequencing data and assess their feasibility with metagenomic next-generation sequencing data from clinical samples. Methods On the basis of 4170 K. pneumoniae genomes, the main genetic characteristics associated with AMR were identified using a LASSO regression model. Consequently, the prediction model was established, validated and optimized using clinical isolate read simulation sequences. To evaluate the efficacy of the model, clinical specimens were collected. Results Four predictive models for amikacin, ciprofloxacin, levofloxacin, and piperacillin/tazobactam, initially had positive predictive values (PPVs) of 92%, 98%, 99%, 94%, respectively, when they were originally constructed. When applied to clinical specimens, their PPVs were 96%, 96%, 95%, and 100%, respectively. Meanwhile, there were negative predictive values (NPVs) of 100% for ciprofloxacin and levofloxacin, and 'not applicable' (NA) for amikacin and piperacillin/tazobactam. Our method achieved antibacterial phenotype classification accuracy rates of 95.92% for amikacin, 96.15% for ciprofloxacin, 95.31% for levofloxacin and 100% for piperacillin/tazobactam. The sequence-based prediction antibiotic susceptibility testing (AST) reported results in an average time of 19.5 h, compared with the 67.9 h needed for culture-based AST, resulting in a significant reduction of 48.4 h. Conclusions These preliminary results demonstrated that the performance of prediction model for a clinically significant antimicrobial–species pair was comparable to that of phenotypic methods, thereby encouraging the expansion of sequence-based susceptibility prediction and its clinical validation and application. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Traditional fermented milks are produced through an inoculation process that involves the deliberate introduction of microorganisms that have been adapted and perpetuated across successive generations. However, the changes in the microbiota of traditional fermented milk during long-term inoculation fermentation in a laboratory environment remain unclear. In this study, we collected 5 samples of traditional fermented milk samples from 5 different counties in Tibet (3 kurut products) and Xinjiang (2 tarag products) of China, which served as starter cultures for a 9-mo continuous inoculation fermentation experiment. We analyzed the inter- and intrapopulation variations in the microbial communities of the collected samples, representing their macrodiversity and microdiversity, using shotgun metagenomic sequencing. Across all samples, we obtained a total of 186 high-quality metagenomic-assembled genomes, including 7 genera and 13 species with a relative abundance of more than 1%. The majority of these genomes were annotated as Lactobacillus helveticus (60.46%), Enterococcus durans (9.52%), and Limosilactobacillus fermentum (6.23%). We observed significant differences in species composition and abundance among the 5 initial inoculants. During the long-term inoculation fermentation, we found an overall increasing trend in species diversity, composition, and abundances of carbohydrate metabolism module-encoding genes in the fermented milk bacterial metagenome, while the fermented milk virome exhibited a relatively narrow range of variation. Lactobacillus helveticus, a dominant species in traditional fermented milk, displayed high stability during the long-term inoculation fermentation. Our study provides valuable insights for the industrial production of traditional fermented milk. [ABSTRACT FROM AUTHOR]

The gut microbiome is linked to osteoporosis. Previous clinical studies showed inconsistent results. This study aimed to characterize the gut microbiota feature and reveal its relation with diet in postmenopausal osteoporosis. Fifty-five postmenopausal women with osteoporosis (Op group) and forty-four age-matched postmenopausal women (normal bone mineral density, Con group) were included in this study. Fecal microbiota was collected and analyzed by shallow shotgun sequencing. Food frequency questionnaires were collected from both groups, and Spearman analysis was used to clarify its correlation with gut microbiota. A total of 2671 species from 29 phyla, 292 families, 152 orders, 80 classes were detected in the study. The two groups had no significant difference in the α and β diversity (p > 0.05). At the genus level, Anaerostipes was enriched in Op group (p < 0.05). At species level, Methanobrevibacter smithii, Bifidobacterium animalis, Rhodococcus defluvii, Lactobacillus plantarum, and Carnobacterium mobile were enriched in the Op group, while Bacillus luciferensis, Acetivibrio cellulolyticus, Citrobacter amalonaticus, and Bifidobacterium breve were differentially enriched in the Con group. Food frequency questionnaire showed that postmenopausal women with osteoporosis intaked more red meat, beer, white and red wine (p < 0.05), and the Con group had more yogurt, fruit, and tea consumption. Red meat consumption had a significant negative correlation with Streptosporangiales (p < 0.01) and Actinomadura (p < 0.05). Fruits intake negatively correlated with Nocardiaceae, Rhodococcus, and Rhodococcus defluvii (p < 0.05). More yogurt intake was consistently correlated with a greater abundance of Streptosporangiales. This study suggests that gut microbiota is significantly altered in the postmenopausal osteoporosis population at genus and species levels, and specific dietary intake might relate to these changes. [ABSTRACT FROM AUTHOR]

Microbial arsenic (As) transformations play a vital role in both driving the global arsenic biogeochemical cycle and determining the mobility and toxicity of arsenic in soils. Due to the complexity of soils, variations in soil characteristics, and the presence and condition of overlying vegetation, soil microbiomes and their functional pathways vary from site to site. Consequently, key arsenic-transforming mechanisms in soil are not well characterized. This study utilized a combination of high-throughput amplicon sequencing and shotgun metagenomics to identify arsenic-transforming pathways in surface agricultural soils. The temporal and successional variations of the soil microbiome and arsenic-transforming bacteria in agricultural soils were examined during tropical monsoonal dry and wet seasons, with a six-month interval. Soil microbiomes of both dry and wet seasons were relatively consistent, particularly the relative abundance of Chloroflexi, Gemmatimonadota, and Bacteroidota. Common bacterial taxa present at high abundance, and potentially capable of arsenic transformations, were Bacillus, Streptomyces, and Microvirga. The resulting shotgun metagenome indicated that among the four key arsenic-functional genes, the arsC gene exhibited the highest relative abundance, followed by the arsM, aioA, and arrA genes, in declining sequence. Gene sequencing data based on 16S rRNA predicted only the arsC and aioA genes. Overall, this study proposed that a cooperative mechanism involving detoxification through arsenate reduction and arsenic methylation was a key arsenic transformation in surface agricultural soils with low arsenic concentration (7.60 to 10.28 mg/kg). This study significantly advances our knowledge of arsenic-transforming mechanisms interconnected with microbial communities in agricultural soil, enhancing pollution control measures, mitigating risks, and promoting sustainable soil management practices. [ABSTRACT FROM AUTHOR]

Background: Polyhydroxyalkanoates (PHAs) are naturally produced biopolymers with significant scientific and biotechnological potential. This study aimed to investigate the diversity of the PHA-producing bacterial community and PhaC genes in soil samples collected from a municipal solid waste disposal site known as "Qoshe" in Addis Ababa, Ethiopia, using a shotgun metagenomics approach. The SqueezeMeta pipeline was used to analyze the microbial community in the waste samples. A CD search against the TIGRFAM protein family database was performed to identify the complete-length multidomain sequences of PhaC genes and classify them into their respective classes. Statistical analysis and data visualization were performed using RStudio with R version 4.2.3. Results: The findings of this study suggest that known and unknown taxa likely contribute to the phaC genes of municipal solid waste. Taxonomic profiling of the metagenomic data revealed that the majority of the PHA-producing taxa belonged to the phylum Proteobacteria (80%), followed by Actinomycetota (16.5%). Furthermore, this study identified Thiomonas and unclassified Mycobacterium as the main contributors to class I PhaC genes. Class II PhaC genes are predominantly associated with the Pseudomonadaceae family, followed by unclassified Hyphomicrobials and Acidimicrobiales. Class III PhaC genes are abundantly related to the Methylococcaceae family, specifically the Methylocaldum genus. The analysis of PhaC gene sequences revealed high level of diversity, with a significant proportion of putative PhaC genes exhibiting low sequence identity with each other and PhaC gene in the database. Notably, the sequence variation observed within the same PhaC gene classes suggests the potential presence of previously unidentified PhaC gene variants. Conclusions: Overall, this research improves our understanding of the diversity of PHA-producing taxa and PhaC genes in municipal solid waste environments, providing opportunities for sustainable PHA production and waste management strategies. However, additional studies, including the isolation and characterization of specific strains, are necessary to confirm the PHA production capabilities of these strains and explore their biotechnological potential. [ABSTRACT FROM AUTHOR]

The impact of pollution on the Ologe Lagoon was assessed by comparing physicochemical properties, hydrocarbon concentrations and microbial community structures of the sediments obtained from distinct sites of the lagoon. The locations were the human activity site (OLHAS), industrial-contaminated sites (OLICS) and relatively undisturbed site (OLPS). The physicochemical properties, heavy metal concentrations and hydrocarbon profiles were determined using standard methods. The microbial community structures of the sediments were determined using shotgun next-generation sequencing (NGS), taxonomic profiling was performed using centrifuge and statistical analysis was done using statistical analysis for metagenomics profile (STAMP) and Microsoft Excel. The result showed acidic pH across all sampling points, while the nitrogen content at OLPS was low (7.44 ± 0.085 mg/L) as compared with OLHAS (44.380 ± 0.962 mg/L) and OLICS (59.485 ± 0.827 mg/L). The levels of the cadmium, lead and nickel in the three sites were above the regulatory limits. The gas chromatography flame ionization detector (GC-FID) profile revealed hydrocarbon contaminations with nC14 tetradecane > alpha xylene > nC9 nonane > acenaphthylene more enriched at OLPS. Structurally, the sediments metagenomes consisted of 43 phyla,75 classes each, 165, 161, 166 orders, 986, 927 and 866 bacterial genera and 1476, 1129, 1327 species from OLHAS, OLICS and OLPS, respectively. The dominant phyla in the sediments were Proteobacteria, Firmicutes, Actinobacteria, and Chloroflexi. The principal component ordination (PCO) showed that OLPS microbial community had a total variance of 87.7% PCO1, setting it apart from OLHAS and OLICS. OLICS and OLHAS were separated by PCO2 accounting for 12.3% variation, and the most polluted site is the OLPS. [ABSTRACT FROM AUTHOR]

The prevalence of pediatric inflammatory bowel disease (pIBD) has been increasing over the last two decades. Yet, treatment strategies are still limited, in part due to the multifactorial nature of the disease and the complex interplay between genetic, environmental, dietary, immune, and gut microbial factors in its etiology. With their direct and indirect anti-inflammatory properties, human milk oligosaccharides (HMOs) are a promising treatment and management strategy for IBD. However, to date there are no insights into how HMOs may affect pIBD microbiota. Here, we compared the effects of 2′fucosyllactose (2′FL), difucosyllactose (DFL), 3′sialyllactose (3′SL), and blends thereof with fructooligosaccharide (FOS) on microbiota functionality (short- and branched-chain fatty acids, pH, and gas production) and composition (quantitative shallow shotgun sequencing) using fecal material from eight different pediatric Crohn's disease patients inoculated in the SIFR® technology. In general, all HMO treatments significantly increased total short-chain fatty acid production when compared with FOS, despite equal gas production. We found that 2′FL, either alone or in combination with DFL and 3′SL, exhibited a strong acetogenic and propiogenic effect, and 3′SL an acetogenic effect that surpassed the effects observed with FOS. No differences in overall community diversity between HMO- and FOS-treated pIBD microbiota were observed. There was, however, a stronger bifidogenic effect of 2′FL, 3′SL, 2′FL/DFL, and 2′FL/DFL + 3′SL when compared with FOS. In general, 3′SL and HMO blends enriched a broader species profile, including taxa with potentially anti-inflammatory properties, such as Faecalibacterium prausnitzii and Blautia species. This study suggests HMOs as a promising strategy to beneficially alter the gut microbial profile in pIBD. [ABSTRACT FROM AUTHOR]

As an omnivorous fish, wild tilapia feed on both animal and plant foods, depending on what is available. To understand the nutritional function of the gut microbiota of tilapia, we used shotgun metagenomic sequencing, untargeted metabolomics analysis, and 16S rRNA gene sequencing to study the metabolites and gut microbial communities in tilapia eating different diets (artemia nauplii in the carnivorous diet; plant‐based pelleted feed [PBP] in the herbivorous diet; and a mixture of these two in the omnivorous diet). A total of 225 Nile tilapia (Oreochromis niloticus) were cultured in nine 1500 L outdoor tanks, with three replicate tanks per diet and 25 fish per tank. β‐diversity analysis revealed that there was no significant difference in microbial structure between the three diets. However, significant differences were detected in gut metabolites. The abundance of the core bacteria in tilapia intestine (genus Cetobacterium) increased significantly when an omnivorous diet was fed. Cetobacterium abundance was significantly correlated to some differential metabolites including glucose and amino acids, and significantly correlated to pathways of carbohydrate and amino acids metabolism, identified by metagenome analysis. Metagenomic binning produced seven Cetobacterium MAGs with the completeness >50% and contamination <10%, in which genes related to the above metabolites and metabolism pathways were identified. All seven MAGs contained CAZymes that could act on distinct carbohydrates, providing highly diversified capabilities to this genus to cope with both animal and plant glycans. These tilapia fed with an omnivorous diet also showed increased growth. The differential intestinal metabolites aspartate, isoleucine, ornithine, proline, nicotinate, and NAD+ could be related to the increased growth. Our results expanded the understanding of how tilapia have adapted to an omnivorous diet and may provide knowledge for improving aquaculture management. [ABSTRACT FROM AUTHOR]

The concept of the gut-kidney axis is gaining significant attention due to the close relationship between gut microbiota and kidney disease. Peritoneal dialysis is recognized as a crucial renal replacement therapy for end-stage renal disease (ESRD). The alterations in gut microbiota and related mechanisms after receiving this dialysis method are not fully understood. This study conducted shotgun metagenomic sequencing on fecal samples from 11 end-stage renal disease patients who did not receive dialysis (ESRD_N) and 7 patients who received peritoneal dialysis (ESRD_P). After quality control and correlation analysis of the data, our study is aimed at exploring the impact of peritoneal dialysis on the gut microbiota and health of ESRD patients. Our research findings indicate that the complexity and aggregation characteristics of gut microbiota interactions increase in ESRD_P. In addition, the gut microbiota drives the biosynthesis pathways of sesquiterpenes and triterpenes in ESRD_P patients, which may contribute to blood purification and improve circulation. Therefore, our research will lay the foundation for the prevention and treatment of ESRD. [ABSTRACT FROM AUTHOR]

The human gut microbiome, crucial for health, can be disrupted by antibiotic treatment, leading to various health issues and the rise of antimicrobial resistance (AMR). This study investigates the impact of a probiotic on the gut microbiome's composition and antimicrobial resistance genes (ARGs) content following antibiotic treatment. Conducted as a single-centre, double-blind, randomized, placebo-controlled trial, adults taking oral antibiotics were allocated into a probiotic or placebo group. Evaluations included viable cell enumeration and shotgun metagenomic sequencing for microbiome analysis, along with ARG assessment. The probiotic maintained the numbers of lactobacilli, significantly increased the Bacteroides population and decreased numbers of enterobacteria. The lactobacilli and enterococci numbers decreased in the placebo. The alpha diversity remained stable in the probiotic group throughout the study, but significant reductions were observed in the placebo group post antibiotic treatment. There was significant spatial separation in beta diversities between groups at the end of the study. Compared to baseline levels, there was a significant reduction in the abundance of ARGs in the probiotic group at the end of the study, while ARG abundance in the placebo group was comparable with baseline levels at the end of the study. Co-occurrence network analysis observed consistent betweenness centrality and node degree within group in the probiotic group whereas scores decreased in the placebo group. This study suggests that the probiotic may minimize the disruption of antibiotic treatment on the gut microbiome by preserving microbial diversity and reducing ARG abundance. [ABSTRACT FROM AUTHOR]

Vaginitis is a widespread issue for women worldwide, yet current diagnostic tools are lacking. Bacterial vaginosis (BV) is the most prevalent type of vaginitis, found in 10–50% of reproductive-aged women. Current diagnostic methods for BV rely on clinical criteria, microscopy, or the detection of a few microbes by qPCR. However, many vaginal infections lack a single etiological agent and are characterized by changes in the vaginal microbiome community structure (e.g., BV is defined as a loss of protective lactobacilli resulting in an overgrowth of anaerobic bacteria). Shotgun metagenomic sequencing provides a comprehensive view of all the organisms present in the vaginal microbiome (VMB), allowing for a better understanding of all potential etiologies. Here, we describe a robust VMB metagenomics sequencing test with a sensitivity of 93.1%, a specificity of 90%, a negative predictive value of 93.4%, and a positive predictive value of 89.6% certified by Clinical Laboratory Improvement Amendments (CLIA), the College of American Pathologist (CAP), and the Clinical Laboratory Evaluation Program (CLEP). We sequenced over 7000 human vaginal samples with this pipeline and described general findings and comparisons to US census data. [ABSTRACT FROM AUTHOR]

Advances in omics technologies have enabled the in-depth study of microbial communities and their metabolic profiles from all environments. Here metagenomes were sampled from piranha (Serrasalmus rhombeus) and from river water from the Rio São Benedito (Amazon Basin). Shotgun metagenome sequencing was used to explore diversity and to test whether fish microbiomes are a good proxy for river microbiome studies. The results showed that the fish microbiomes were not significantly different from the river water microbiomes at higher taxonomic ranks. However, at the genus level, fish microbiome alpha diversity decreased, and beta diversity increased. This result repeated for functional gene abundances associated with specific metabolic categories (SEED level 3). A clear delineation between water and fish was seen for beta diversity. The piranha microbiome provides a good and representative subset of its river water microbiome. Variations seen in beta biodiversity were expected and can be explained by temporal variations in the fish microbiome in response to stronger selective forces on its biodiversity. Metagenome assembled genomes construction was better from the fish samples. This study has revealed that the microbiome of a piranha tells us a lot about its river water microbiome and function. [ABSTRACT FROM AUTHOR]

Background: The infant gut microbiome's establishment is pivotal for health and immune development. Understanding it unveils insights into growth, development, and maternal microbial interactions. Research often emphasizes gut bacteria, neglecting the phageome. Methods: To investigate the influence of geographic or maternal factors (mode of delivery, mode of breastfeeding, gestational diabetesmellitus) on the gut microbiota and phages of newborns, we collected fecal samples from 34 pairs of mothers and their infants within 24 hours of delivery from three regions (9 pairs from Enshi, 7 pairs from Hohhot, and 18 pairs from Hulunbuir) using sterile containers. Gut microbiota analysis by Shotgun sequencing was subsequently performed. Results: Our results showed that geographic location affects maternal gut microbiology (P < 0.05), while the effect on infant gut microbiology was not significant (P = 0.184). Among the maternal factors, mode of delivery had a significant (P < 0.05) effect on the newborn. Specific bacteria (e.g., Bacteroides, Escherichia spp., Phocaeicola vulgatus, Escherichia coli, Staphylococcus hominis, Veillonella spp.), predicted active metabolites, and bacteriophage vOTUs varied with delivery mode. Phocaeicola vulgatus significantly correlated with some metabolites and bacteriophages in the early infant gut (P < 0.05). In the GD group, a strong negative correlation of phage diversity between mother and infants was observed (R = -0.58, P=0.04). Conclusion: In conclusion, neonatal early gut microbiome (including bacteria and bacteriophages) colonization is profoundly affected by the mode of delivery, and maternal gestational diabetes mellitus. The key bacteria may interact with bacteriophages to influence the levels of specific metabolites. Our study provides new evidence for the study of the infant microbiome, fills a gap in the analysis of the infant gut microbiota regarding the virome, and emphasizes the importance of maternal health for the infant initial gut virome. [ABSTRACT FROM AUTHOR]

The rhizosphere, the soil region influenced by plant roots, represents a dynamic microenvironment where intricate interactions between plants and microorganisms shape soil health, nutrient cycling, and plant growth. Soil microorganisms are integral players in the transformation of materials, the dynamics of energy flows, and the intricate cycles of biogeochemistry. Considerable research has been dedicated to investigating the abundance, diversity, and intricacies of interactions among different microbes, as well as the relationships between plants and microbes present in the rhizosphere. Metagenomics, a powerful suite of techniques, has emerged as a transformative tool for dissecting the genetic repertoire of complex microbial communities inhabiting the rhizosphere. The review systematically navigates through various metagenomic approaches, ranging from shotgun metagenomics, enabling unbiased analysis of entire microbial genomes, to targeted sequencing of the 16S rRNA gene for taxonomic profiling. Each approach's strengths and limitations are critically evaluated, providing researchers with a nuanced understanding of their applicability in different research contexts. A central focus of the review lies in the practical applications of rhizosphere metagenomics in various fields including agriculture. By decoding the genomic content of rhizospheric microbes, researchers gain insights into their functional roles in nutrient acquisition, disease suppression, and overall plant health. The review also addresses the broader implications of metagenomic studies in advancing our understanding of microbial diversity and community dynamics in the rhizosphere. It serves as a comprehensive guide for researchers, agronomists, and policymakers, offering a roadmap for harnessing metagenomic approaches to unlock the full potential of the rhizosphere microbiome in promoting sustainable agriculture. [ABSTRACT FROM AUTHOR]

Background: Environmental reservoirs of antibiotic resistance pose a threat to human and animal health. Aquatic biofilms impacted by wastewater effluent (WW) are known environmental reservoirs for antibiotic resistance; however, the relative importance of biotic factors and abiotic factors from WW on the abundance of antibiotic resistance genes (ARGs) within aquatic biofilms remains unclear. Additionally, experimental evidence is limited within complex aquatic microbial communities as to whether genes bearing low sequence similarity to validated reference ARGs are functional as ARGs. Results: To disentangle the effects of abiotic and biotic factors on ARG abundances, natural biofilms were previously grown in flume systems with different proportions of stream water and either ultrafiltered or non-ultrafiltered WW. In this study, we conducted deep shotgun metagenomic sequencing of 75 biofilm, stream, and WW samples from these flume systems and compared the taxonomic and functional microbiome and resistome composition. Statistical analysis revealed an alignment of the resistome and microbiome composition and a significant association with experimental treatment. Several ARG classes exhibited an increase in normalized metagenomic abundances in biofilms grown with increasing percentages of non-ultrafiltered WW. In contrast, sulfonamide and extended-spectrum beta-lactamase ARGs showed greater abundances in biofilms grown in ultrafiltered WW compared to non-ultrafiltered WW. Overall, our results pointed toward the dominance of biotic factors over abiotic factors in determining ARG abundances in WW-impacted stream biofilms and suggested gene family-specific mechanisms for ARGs that exhibited divergent abundance patterns. To investigate one of these specific ARG families experimentally, we biochemically characterized a new beta-lactamase from the Planctomycetota (Phycisphaeraceae). This beta-lactamase displayed activity in the cleavage of cephalosporin analog despite sharing a low sequence identity with known ARGs. Conclusions: This discovery of a functional planctomycete beta-lactamase ARG is noteworthy, not only because it was the first beta-lactamase to be biochemically characterized from this phylum, but also because it was not detected by standard homology-based ARG tools. In summary, this study conducted a metagenomic analysis of the relative importance of biotic and abiotic factors in the context of WW discharge and their impact on both known and new ARGs in aquatic biofilms. DkJa1T-YWptaXXeH_hsDtB Video Abstract [ABSTRACT FROM AUTHOR]

Background: Limited data exists regarding gender-specific microbial alterations during gender-affirming hormonal therapy (GAHT) in transgender individuals. This study aimed to investigate the nuanced impact of sex steroids on gut microbiota taxonomy and function, addressing this gap. We prospectively analyzed gut metagenome changes associated with 12 weeks of GAHT in trans women and trans men, examining both taxonomic and functional shifts. Methods: Thirty-six transgender individuals (17 trans women, 19 trans men) provided pre- and post-GAHT stool samples. Shotgun metagenomic sequencing was used to assess the changes in gut microbiota structure and potential function following GAHT. Results: While alpha and beta diversity remained unchanged during transition, specific species, including Parabacteroides goldsteinii and Escherichia coli, exhibited significant abundance shifts aligned with affirmed gender. Overall functional metagenome analysis showed a statistically significant effect of gender and transition (R2 = 4.1%, P = 0.0115), emphasizing transitions aligned with affirmed gender, particularly in fatty acid-related metabolism. Conclusions: This study provides compelling evidence of distinct taxonomic and functional profiles in the gut microbiota between trans men and women. GAHT induces androgenization in trans men and feminization in trans women, potentially impacting physiological and health-related outcomes. Trial registration: Clinicaltrials.gov NCT02185274. [ABSTRACT FROM AUTHOR]

Microbial metabolites can be viewed as the cytokines of the microbiome, transmitting information about the microbial and metabolic environment of the gut to orchestrate and modulate local and systemic immune responses. Still, many immunology studies focus solely on the taxonomy and community structure of the gut microbiota rather than its functions. Early sequencing‐based microbiota profiling approaches relied on PCR amplification of small regions of bacterial and fungal genomes to facilitate identification of the microbes present. However, recent microbiome analysis methods, particularly shotgun metagenomic sequencing, now enable culture‐independent profiling of microbiome functions and metabolites in addition to taxonomic characterization. In this review, we showcase recent advances in functional metagenomics methods and applications and discuss the current limitations and potential avenues for future development. Importantly, we highlight a few examples of key areas of opportunity in immunology research where integrating functional metagenomic analyses of the microbiome can substantially enhance a mechanistic understanding of microbiome–immune interactions and their contributions to health and disease states. [ABSTRACT FROM AUTHOR]

Despite a surge in microbiota‐focused studies in teleosts, few have reported functional data on whole metagenomes as it has proven difficult to extract high biomass microbial DNA from fish intestinal samples. The zebrafish is a promising model organism in functional microbiota research, yet studies on the functional landscape of the zebrafish gut microbiota through shotgun based metagenomics remain scarce. Thus, a consensus on an appropriate sampling method accurately representing the zebrafish gut microbiota, or any fish species is lacking. Addressing this, we systematically tested four methods of sampling the zebrafish gut microbiota: collection of faeces from the tank, the whole gut, intestinal content, and the application of ventral pressure to facilitate extrusion of gut material. Additionally, we included water samples as an environmental control to address the potential influence of the environmental microbiota on each sample type. To compare these sampling methods, we employed a combination of genome‐resolved metagenomics and 16S metabarcoding techniques. We observed differences among sample types on all levels including sampling, bioinformatic processing, metagenome co‐assemblies, generation of metagenome‐assembled genomes (MAGs), functional potential, MAG coverage, and population level microdiversity. Comparison to the environmental control highlighted the potential impact of the environmental contamination on data interpretation. While all sample types tested are informative about the zebrafish gut microbiota, the results show that optimal sample type for studying fish microbiomes depends on the specific objectives of the study, and here we provide a guide on what factors to consider for designing functional metagenome‐based studies on teleost microbiomes. [ABSTRACT FROM AUTHOR]

Lung transplant recipients are traditionally monitored with pulmonary function testing (PFT) and lung biopsy to detect post-transplant complications and guide treatment. Plasma donor-derived cell free DNA (dd-cfDNA) is a novel molecular approach of assessing allograft injury, including subclinical allograft dysfunction. The aim of this study was to determine if episodes of extreme molecular injury (EMI) in lung transplant recipients increases the risk of chronic lung allograft dysfunction (CLAD) or death. This multicenter prospective cohort study included 238 lung transplant recipients. Serial plasma samples were collected for dd-cfDNA measurement by shotgun sequencing. EMI was defined as a dd-cfDNA above the third quartile of levels observed for acute rejection (dd-cfDNA level of ≥5% occurring after 45 days post-transplant). EMI was categorized as Secondary if associated with co-existing acute rejection, infection or PFT decline; or Primary if not associated with these conditions. EMI developed in 16% of patients at a median 343.5 (IQR: 177.3–535.5) days post-transplant. Over 50% of EMI episodes were classified as Primary. EMI was associated with an increased risk of severe CLAD or death (HR: 2.78, 95% CI: 1.26–6.22, p = 0.012). The risk remained consistent for the Primary EMI subgroup (HR: 2.34, 95% CI 1.18–4.85, p = 0.015). Time to first EMI episode was a significant predictor of the likelihood of developing CLAD or death (AUC = 0.856, 95% CI = 0.805–0.908, p < 0.001). Episodes of EMI in lung transplant recipients are often isolated and may not be detectable with traditional clinical monitoring approaches. EMI is associated with an increased risk of severe CLAD or death, independent of concomitant transplant complications. [ABSTRACT FROM AUTHOR]

Forensic microbiology is rapidly emerging as a novel tool for human identification. The human microbiome, comprising diverse microbial communities including fungi, bacteria, protozoa, and viruses, is unique to each individual, offering a new dimension to forensic investigations. While traditional identification methods primarily rely on DNA profiling and fingerprint analysis, they face limitations when complete DNA or fingerprints profiles are unattainable or degraded. In this context, the microbial signatures of the human skin microbiome present a promising alternative due to their resilience to environmental stresses and individual-specific composition. This review explores the potential of microbiome analysis in forensic human identification, evaluating its applications, advantages, limitations, and future prospects. The uniqueness of an individual's microbial community, particularly the skin microbiota, can provide distinctive biological markers for identification purposes, while technological advancements like 16 S rRNA sequencing and metagenomic shotgun sequencing are enhancing the specificity of microbial identification, enabling detailed analysis of these complex ecological communities. Despite these promising findings, current research has not yet achieved a level of identification probability that could establish microbial analysis as a stand-alone evidence tool. Therefore, it is presently considered ancillary to traditional methods, contributing to a more comprehensive biological profile of individuals. [ABSTRACT FROM AUTHOR]

Therapeutic messenger RNAs (mRNAs) have emerged as powerful tools in the treatment of complex diseases, especially for conditions that lack efficacious treatment. The successful application of this modality can be attributed to its ability to encode entire proteins. While the large nature of these molecules has supported their success as therapeutics, its extended size creates several analytical challenges. To further support therapeutic mRNA development and its deployment in clinical trials, appropriate methods to support their characterization must be developed. In this review, we describe current analytical methods that have been used in the characterization of RNA quality, identity, and integrity. Advantages and limitations from several analytical techniques ranging from gel electrophoresis to liquid chromatography–mass spectrometry and from shotgun sequencing to intact mass measurements are discussed. We comprehensively describe the application of analytical methods in the measurements of capping efficiency, poly A tail analysis, as well as their applicability in stability studies. [ABSTRACT FROM AUTHOR]

Background: The Neotropics harbors the largest species richness of the planet; however, even in well-studied groups, there are potentially hundreds of species that lack a formal description, and likewise, many already described taxa are difficult to identify using morphology. Specifically in small mammals, complex morphological diagnoses have been facilitated by the use of molecular data, particularly from mitochondrial sequences, to obtain accurate species identifications. Obtaining mitochondrial markers implies the use of PCR and specific primers, which are largely absent for non-model organisms. Oxford Nanopore Technologies (ONT) is a new alternative for sequencing the entire mitochondrial genome without the need for specific primers. Only a limited number of studies have employed exclusively ONT long-reads to assemble mitochondrial genomes, and few studies have yet evaluated the usefulness of such reads in multiple non-model organisms. Methods: We implemented fieldwork to collect small mammals, including rodents, bats, and marsupials, in five localities in the northern extreme of the Cordillera Central of Colombia. DNA samples were sequenced using the MinION device and Flongle flow cells. Shotgun-sequenced data was used to reconstruct the mitochondrial genome of all the samples. In parallel, using a customized computational pipeline, species-level identifications were obtained based on sequencing raw reads (Whole Genome Sequencing). ONT-based identifications were corroborated using traditional morphological characters and phylogenetic analyses. Results: A total of 24 individuals from 18 species were collected, morphologically identified, and deposited in the biological collection of Universidad EAFIT. Our different computational pipelines were able to reconstruct mitochondrial genomes from exclusively ONT reads. We obtained three new mitochondrial genomes and eight new molecular mitochondrial sequences for six species. Our species identification pipeline was able to obtain accurate species identifications for up to 75% of the individuals in as little as 5 s. Finally, our phylogenetic analyses corroborated the identifications from our automated species identification pipeline and revealed important contributions to the knowledge of the diversity of Neotropical small mammals. Discussion: This study was able to evaluate different pipelines to reconstruct mitochondrial genomes from non-model organisms, using exclusively ONT reads, benchmarking these protocols on a multi-species dataset. The proposed methodology can be applied by non-expert taxonomists and has the potential to be implemented in real-time, without the need to euthanize the organisms and under field conditions. Therefore, it stands as a relevant tool to help increase the available data for non-model organisms, and the rate at which researchers can characterize life specially in highly biodiverse places as the Neotropics. [ABSTRACT FROM AUTHOR]

Abstract Background Polyhydroxyalkanoates (PHAs) are naturally produced biopolymers with significant scientific and biotechnological potential. This study aimed to investigate the diversity of the PHA-producing bacterial community and PhaC genes in soil samples collected from a municipal solid waste disposal site known as “Qoshe” in Addis Ababa, Ethiopia, using a shotgun metagenomics approach. The SqueezeMeta pipeline was used to analyze the microbial community in the waste samples. A CD search against the TIGRFAM protein family database was performed to identify the complete-length multidomain sequences of PhaC genes and classify them into their respective classes. Statistical analysis and data visualization were performed using RStudio with R version 4.2.3. Results The findings of this study suggest that known and unknown taxa likely contribute to the phaC genes of municipal solid waste. Taxonomic profiling of the metagenomic data revealed that the majority of the PHA-producing taxa belonged to the phylum Proteobacteria (80%), followed by Actinomycetota (16.5%). Furthermore, this study identified Thiomonas and unclassified Mycobacterium as the main contributors to class I PhaC genes. Class II PhaC genes are predominantly associated with the Pseudomonadaceae family, followed by unclassified Hyphomicrobials and Acidimicrobiales. Class III PhaC genes are abundantly related to the Methylococcaceae family, specifically the Methylocaldum genus. The analysis of PhaC gene sequences revealed high level of diversity, with a significant proportion of putative PhaC genes exhibiting low sequence identity with each other and PhaC gene in the database. Notably, the sequence variation observed within the same PhaC gene classes suggests the potential presence of previously unidentified PhaC gene variants. Conclusions Overall, this research improves our understanding of the diversity of PHA-producing taxa and PhaC genes in municipal solid waste environments, providing opportunities for sustainable PHA production and waste management strategies. However, additional studies, including the isolation and characterization of specific strains, are necessary to confirm the PHA production capabilities of these strains and explore their biotechnological potential.

Digital information encoded in polymers has been exclusively decoded by mass spectrometry. However, the size limit of analytes in mass spectrometry restricts the storage capacity per chain. In addition, sequential decoding hinders random access to the bits of interest without full‐chain sequencing. Here we report the shotgun sequencing of a 512‐mer sequence‐defined polymer whose molecular weight (57.3 kDa) far exceeds the analytical limit of mass spectrometry. A 4‐bit fragmentation code was implemented at aperiodic positions during the synthetic encoding of 512‐bit information without affecting storage capacity per chain. Upon activating the fragmentation code, the polymer chain splits into 18 oligomers, which could be individually decoded by tandem‐mass sequencing. These sequences were computationally reconstructed into a full sequence using an error‐detection method. The proposed sequencing method eliminates the storage limit of a single polymer chain and allows random access to the bits of interest without full‐chain sequencing. [ABSTRACT FROM AUTHOR]

Halophyte shrubs, prevalent in arid regions globally, create saline fertile islands under their canopy. This study investigates the soil microbial communities and their energy utilization strategies associated with tamarisk shrubs in arid ecosystems. Shotgun sequencing revealed that high salinity in tamarisk islands reduces functional gene alpha-diversity and relative abundance compared to bare soils. However, organic matter accumulation within islands fosters key halophilic archaea taxa such as Halalkalicoccus, Halogeometricum, and Natronorubrum, linked to processes like organic carbon oxidation, nitrous oxide reduction, and sulfur oxidation, potentially strengthening the coupling of nutrient cycles. In contrast, bare soils harbor salt-tolerant microbes with genes for autotrophic energy acquisition, including carbon fixation, H2 or CH4 consumption, and anammox. Additionally, isotope analysis shows higher microbial carbon use efficiency, N mineralization, and denitrification activity in tamarisk islands. Our findings demonstrate that halophyte shrubs serve as hotspots for halophilic microbes, enhancing microbial nutrient transformation in saline soils. Halophyte shrubs serve as hotspots for halophilic microbes, enhancing microbial nutrient transformation in saline soils. [ABSTRACT FROM AUTHOR]

The increasing prevalence of gut colonization with CTX-M extended-spectrum β-lactamase- and/or DHA plasmid-mediated AmpC-producing Escherichia coli is a concern. Here, we evaluate Nanopore-shotgun metagenomic sequencing (Nanopore-SMS) latest V14 chemistry to detect blaCTX-M and blaDHA genes from healthy stools. We test 25 paired samples characterized with culture-based methods (native and pre-enriched). Antimicrobial resistant genes (ARGs) are detected from reads and meta-assembled genomes (MAGs) to determine their associated genetic environments (AGEs). Sensitivity and specificity of native Nanopore-SMS are 61.1% and 100%, compared to 81.5% and 75% for pre-enriched Nanopore-SMS, respectively. Native Nanopore-SMS identifies only one sample with an AGE, whereas pre-enriched Nanopore-SMS recognizes 9/18 plasmids and 5/9 E. coli chromosomes. Pre-enriched Nanopore-SMS identifies more ARGs than native Nanopore-SMS (p < 0.001). Notably, blaCTX-Ms and blaDHAs AGEs (plasmid and chromosomes) are identified within 1 hour of sequencing. Furthermore, microbiota analyses show that pre-enriched Nanopore-SMS results in more E. coli classified reads (47% vs. 3.1%), higher differential abundance (5.69 log2 fold) and lower Shannon diversity index (p < 0.0001). Nanopore-SMS has the potential to be used for intestinal colonization screening. However, sample pre-enrichment is necessary to increase sensitivity. Further computational improvements are needed to reduce the turnaround time for clinical applications. In this work, authors employ Nanopore-based shotgun metagenomic sequencing for the screening of antimicrobial resistance genes (blaCTX-M/blaDHA) in human stool samples. [ABSTRACT FROM AUTHOR]

Background: Colonic diverticulosis, the most common lesion found in routine colonoscopy, affects more than 50% of individuals aged ≥ 60 years. Emerging evidence suggest that dysbiosis of gut microbiota may play an important role in the pathophysiology of diverticular disease. However, specific changes in microbial species and metabolic functions in asymptomatic diverticulosis remain unknown. Methods: In a cohort of US adults undergoing screening colonoscopy, we analyzed the gut microbiota using shotgun metagenomic sequencing. Demographic factors, lifestyle, and medication use were assessed using a baseline questionnaire administered prior to colonoscopy. Taxonomic structures and metabolic pathway abundances were determined using MetaPhlAn3 and HUMAnN3. We used multivariate association with linear models to identify microbial species and metabolic pathways that were significantly different between asymptomatic diverticulosis and controls, while adjusting for confounders selected a priori including age at colonoscopy, sex, body mass index (BMI), and dietary pattern. Results: Among 684 individuals undergoing a screening colonoscopy, 284 (42%) had diverticulosis. Gut microbiome composition explained 1.9% variation in the disease status of asymptomatic diverticulosis. We observed no significant differences in the overall diversity of gut microbiome between asymptomatic diverticulosis and controls. However, microbial species Bifidobacterium pseudocatenulatum and Prevotella copri were significantly enriched in controls (q value = 0.19 and 0.14, respectively), whereas Roseburia intestinalis, Dorea sp. CAG:317, and Clostridium sp. CAG: 299 were more abundant in those with diverticulosis (q values = 0.17, 0.24, and 0.10, respectively). We observed that the relationship between BMI and diverticulosis appeared to be limited to carriers of Bifidobacterium pseudocatenulatum and Roseburia intestinalis (Pinteraction = 0.09). Conclusions: Our study provides the first large-scale evidence supporting taxonomic and functional shifts of the gut microbiome in individuals with asymptomatic diverticulosis. The suggestive interaction between gut microbiota and BMI on prevalent diverticulosis deserves future investigations. [ABSTRACT FROM AUTHOR]

Bumblebees are key pollinators with gut microbiotas that support host health. After bumblebee queens undergo winter diapause, which occurs before spring colony establishment, their gut microbiotas are disturbed, but little is known about community dynamics during diapause itself. Queen gut microbiotas also help seed worker microbiotas, so it is important that they recover post‐diapause to a typical community structure, a process that may be impeded by pesticide exposure. We examined how bumblebee queen gut microbiota community structure and metabolic potential shift during and after winter diapause, and whether post‐diapause recovery is affected by pesticide exposure. To do so, we placed commercial Bombus impatiens queens into diapause, euthanizing them at 0, 2 and 4 months of diapause. Additionally, we allowed some queens to recover from diapause for 1 week before euthanasia, exposing half to the common herbicide glyphosate. Using whole‐community, shotgun metagenomic sequencing, we found that core bee gut phylotypes dominated queen gut microbiotas before, during and after diapause, but that two phylotypes, Schmidhempelia and Snodgrassella, ceased to be detected during late diapause and recovery. Despite fluctuations in taxonomic community structure, metabolic potential remained constant through diapause and recovery. Also, glyphosate exposure did not affect post‐diapause microbiota recovery. However, metagenomic assembly quality and our ability to detect microbial taxa and metabolic pathways declined alongside microbial abundance, which was substantially reduced during diapause. Our study offers new insights into how bumblebee queen gut microbiotas change taxonomically and functionally during a key life stage and provides guidance for future microbiota studies in diapausing bumblebees. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore the correlation between microbiota dysbiosis and hypothyroidism in early pregnancy by 16S rRNA amplicon sequencing combined with metagenomic sequencing. Methods: Sixty pregnant women (30 with hypothyroidism and 30 normal controls) were recruited for 16S rRNA amplicon sequencing, and 6 patients from each group were randomly selected for metagenomic sequencing to assess the gut microbiome profile. Results: The 16S rRNA results showed that beta-diversity in the hypothyroidism groupwas decreased. The relative abundances of the Prevotella and Paraprevotella genera increased in the hypothyroidism group, and Blautia predominated in the controls. The metagenomics results revealed that Prevotella_stercorea_CAG_629, Prevotella_hominis, Prevotella_sp_AM34_19LB, etc. were enriched in the hypothyroidism group at the species level. Functional analysis revealed that the pyridoxal 5'-phosphate synthase pdxT subunit module was decreased, and the short-chain fatty acid (SCFA) transporter and phospholipase/carboxylesterase modules were strongly enriched in the hypothyroidism group. Hypothyroidism patients had increased C-reactive protein (CRP), interleukin-2 (IL-2), IL-4, IL-10, and tumor necrosis factor (TNF)-α levels. The pyridoxal 5'-phosphate synthase pdxT subunit, the SCFA transporter, and the phospholipase/carboxylesterase module were associated with different Prevotella species. Conclusion: In early pregnancy, women with hypothyroidism exhibit microbiota dysbiosis, and Prevotella may affect the metabolism of glutamate, SCFA, and phospholipases, which could be involved in the development of hypothyroidism during pregnancy. [ABSTRACT FROM AUTHOR]

Obesity is characterized by specific changes in the composition of the gut microbiota (GM). Exercise can contribute to the modulation of GM. This is the first case study to analyze the composition and metabolism of the GM of an obese runner in a single‐stage mountain ultramarathon (MUM) with a mileage of 217 km. Fecal samples were collected 7 days before the race (T0), 15 min after the end of the race (T1), and 7 days after the end of the race (T2). GM composition was analyzed by real‐time PCR and shotgun sequencing. We observed a decrease in Bacillota/Bacteroidota ratio and α‐diversity after the race. After the 217‐km MUM, we observed a decrease in symbiont microorganisms and a notable increase in harmful bacteria. In conclusion, we found that the 217‐km MUM may have contributed to the intestinal dysbiosis of the obese runner. [ABSTRACT FROM AUTHOR]

Microbes found in soil can have a significant impact on the taste and quality of wine, also referred to as wine terroir. To date, wine terroir has been thought to be associated with the physical and chemical characteristics of the soil. However, there is a fragmented understanding of the contribution of vineyard soil microbes to wine terroir. Additionally, vineyards can play an important role in carbon sequestration since the promotion of healthy soil and microbial communities directly impacts greenhouse gas emissions in the atmosphere. We review 24 studies that explore the role of soil microbial communities in vineyards and their influence on grapevine health, grape composition, and wine quality. Studies spanning 2015 to 2018 laid a foundation by exploring soil microbial biogeography in vineyards, vineyard management effects, and the reservoir function of soil microbes for grape-associated microbiota. On the other hand, studies spanning 2019 to 2023 appear to have a more specific and targeted approach, delving into the relationships between soil microbes and grape metabolites, the microbial distribution at different soil depths, and microbial influences on wine flavor and composition. Next, we identify research gaps and make recommendations for future work. Specifically, most of the studies utilize targeted sequencing (16S, 26S, ITS), which only reveals community composition. Utilizing high-throughput omics approaches such as shotgun sequencing (to infer function) and transcriptomics (for actual function) is vital to determining the specific mechanisms by which soil microbes influence grape chemistry. Going forward, understanding the long-term effects of vineyard management practices and climate change on soil microbiology, grapevine trunk diseases, and the role of bacteriophages in vineyard soil and wine-making would be a fruitful investigation. Overall, the studies presented shed light on the importance of soil microbiomes and their interactions with grapevines in shaping wine production. However, there are still many aspects of this complex ecosystem that require further exploration and understanding to support sustainable viticulture and enhance wine quality. [ABSTRACT FROM AUTHOR]

Colonization of the infant gut is an important developmental process characterized by high carriage of antimicrobial resistance genes (ARGs) and high abundances of pathobionts. The horizontal transfer of ARGs to pathogenic bacteria represents a major public health concern. However, there is still a paucity of longitudinal studies surveilling ARGs in healthy infant guts at high temporal resolution. Furthermore, we do not yet have a clear view of how temporal variation in ARG carriage relates to the dynamics of specific bacterial populations, as well as community virulence potential. Here, we performed deep shotgun metagenomic sequencing of monthly fecal samples from a cohort of 12 infants, covering the first year of life to interrogate the infant gut microbiome for ARG content. We further relate ARG dynamics to the dynamics of taxa, virulence potential, as well as the potential for ARG mobilization. We identify a core resistome dominated by efflux systems typically associated with Enterobacteriaceae. Overall ARG carriage declined over the first year of life and showed strong contemporaneous correlation with the population dynamics of Proteobacteria. Furthermore, the majority of ARGs could be further mapped to metagenome-assembled genomes (MAGs) classified to this phylum. We were able to assign a large number of ARGs to E. coli by correlating the temporal dynamics of individual genes with species dynamics, and we show that the temporal dynamics of ARGs and virulence factors are highly correlated, suggesting close taxonomic associations between these two gene classes. Finally, we identify ARGs linked with various categories of mobile genetic elements, demonstrating preferential linkage among mobility categories and resistance to different drug classes. While individual variation in ARG carriage is substantial during infancy there is a clear reduction over the first year of life. With few exceptions, ARG abundances closely track the dynamics of pathobionts and community virulence potential. These findings emphasize the potential for development of resistant pathogens in the developing infant gut, and the importance of effective surveillance in order to detect such events. [ABSTRACT FROM AUTHOR]