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Lard diet (LD) is a risk factor for prostate cancer (PCa) development and progression. Two immunocompetent mouse models fed with isocaloric specific fat diets (LD) enriched in saturated and monounsaturated fatty acid (SMFA), showed significanftly enhanced PCa progression with weight gain compared with a fish oil diet (FOD). High gut microbial divergency resulted from difference in diets, and the abundance of several bacterial species, such as in the orders Clostridiales and Lactobacillales, was markedly altered in the feces of LD- or FOD-fed mice. The proportion of the order Lactobacillales in the gut was negatively involved in SMFA-induced body weight gain and PCa progression. We found the modulation of lipid metabolism and cholesterol biosynthesis pathways with three and seven commonly up- and downregulated genes in PCa tissues, and some of them correlated with the abundance of the order Lactobacillales in mouse gut. The expression of sphingosine 1-phosphate receptor 2, which is associated with the order Lactobacillales and cancer progression in mouse models, was inversely associated with aggressive phenotype and weight gain in patients with PCa using the NCBI Gene Expression Omnibus database. Therefore, SMFA may promote PCa progression with the abundance of specific gut microbial species and overexpression of lipogenic genes in PCa. Therapeutics with alteration of gut microbiota and candidate genes involved in diet-induced PCa progression may be attractive in PCa.

Purpose: To determine the possible microbiome related to Vogt-Koyanagi-Harada (VKH) disease in comparison to patients with noninfectious anterior scleritis and healthy people., Methods: Fecal samples were extracted from 42 individuals, including 11 patients with active VKH, 11 healthy people, and 20 patients with noninfectious anterior scleritis. We amplified the V3 to V4 16S ribosomal DNA (rDNA) region to obtain the target sequence. Then, the target sequence was amplified by polymerase chain reaction. The obtained target sequences were sequenced by high-throughput 16S rDNA analysis., Results: At the genus level, there were three enriched (Stomatobaculum, Pseudomonas, Lachnoanaerobaculum) and two depleted (Gordonibacter, Slackia) microbes that were detected only in patients with VKH. There were 10 enriched and 12 depleted microbes that were observed in both patients with VKH disease and noninfectious anterior scleritis (P < 0.05). The interactions of these microbes were graphed. Tyzzerella and Eggerthella were the nodes of interaction between these microorganisms, which were regulated by both positive and negative aspects, but the expression level in patients with active VKH was upregulated., Conclusions: Special or nonspecial enrichment and decreased intestinal microbes were observed in patients with active VKH. The action mechanism of these microbes needs further study.

The gut commensal Anaerobutyricum soehngenii is an anaerobe that can produce both propionate and butyrate, metabolites that have been shown to have a positive effect on gut and overall health. Murine and human dose finding studies have shown that oral intake of A. soehngenii has a positive influence on peripheral insulin resistance, thereby reducing the risk of type 2 diabetes. A recent human intervention provided support for the mode of action of A. soehngenii as it affected gene expression in the duodenum, stimulated the secretion of GLP-1 and improved insulin sensitivity. For these reasons A. soehngenii has been proposed as a food ingredient. Before introducing this bacterium to the food chain, however, it must be established that oral intake of live A. soehngenii bacteria does not pose any health risk. As part of the safety analysis of A. soehngenii strain CH106, we performed genotoxicity assays to determine its mutagenic potential (bacterial reverse mutation and in vitro mammalian cell micronucleus tests) and a 90-day subchronic toxicity study in rats to determine overall toxicity potential. The results of both genotoxicity studies were negative, showing no genotoxic effects. For the 90-day subchronic toxicity study, no adverse events were registered that could be attributed to the feeding with A. soehngenii strain CH106. Even at the highest dose, which exceeds the expected daily human intake more than 100-fold, no adverse events were observed. These result support the conclusion that the use of A. soehngenii strain CH106 as a food ingredient is safe., (© 2021 Caleus Pharmaceuticals BV. Journal of Applied Toxicology published by John Wiley & Sons Ltd.)

Human genetic variation affects the gut microbiota through a complex combination of environmental and host factors. Here we characterize genetic variations associated with microbial abundances in a single large-scale population-based cohort of 5,959 genotyped individuals with matched gut microbial metagenomes, and dietary and health records (prevalent and follow-up). We identified 567 independent SNP-taxon associations. Variants at the LCT locus associated with Bifidobacterium and other taxa, but they differed according to dairy intake. Furthermore, levels of Faecalicatena lactaris associated with ABO, and suggested preferential utilization of secreted blood antigens as energy source in the gut. Enterococcus faecalis levels associated with variants in the MED13L locus, which has been linked to colorectal cancer. Mendelian randomization analysis indicated a potential causal effect of Morganella on major depressive disorder, consistent with observational incident disease analysis. Overall, we identify and characterize the intricate nature of host-microbiota interactions and their association with disease., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

The human gut symbiont Ruminococcus gnavus displays strain-specific repertoires of glycoside hydrolases (GHs) contributing to its spatial location in the gut. Sequence similarity network analysis identified strain-specific differences in blood-group endo-β-1,4-galactosidase belonging to the GH98 family. We determined the substrate and linkage specificities of GH98 from R. gnavus ATCC 29149, RgGH98, against a range of defined oligosaccharides and glycoconjugates including mucin. We showed by HPAEC-PAD and LC-FD-MS/MS that RgGH98 is specific for blood group A tetrasaccharide type II (BgA II). Isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR confirmed RgGH98 affinity for blood group A over blood group B and H antigens. The molecular basis of RgGH98 strict specificity was further investigated using a combination of glycan microarrays, site-directed mutagenesis, and X-ray crystallography. The crystal structures of RgGH98 in complex with BgA trisaccharide (BgAtri) and of RgGH98 E411A with BgA II revealed a dedicated hydrogen network of residues, which were shown by site-directed mutagenesis to be critical to the recognition of the BgA epitope. We demonstrated experimentally that RgGH98 is part of an operon of 10 genes that is overexpresssed in vitro when R. gnavus ATCC 29149 is grown on mucin as sole carbon source as shown by RNAseq analysis and RT-qPCR confirmed RgGH98 expression on BgA II growth. Using MALDI-ToF MS, we showed that RgGH98 releases BgAtri from mucin and that pretreatment of mucin with RgGH98 confered R. gnavus E1 the ability to grow, by enabling the E1 strain to metabolise BgAtri and access the underlying mucin glycan chain. These data further support that the GH repertoire of R. gnavus strains enable them to colonise different nutritional niches in the human gut and has potential applications in diagnostic and therapeutics against infection., Competing Interests: The authors have declared that no competing interests exist.

Objective: The primary aim of this investigation was to analyze the microbiome in patients with combined periodontal-endodontic lesions., Method: Patients with loose and/or painful teeth referred for treatment from March 2020 to December 2020 in the First People's Hospital of Jinzhong were recruited. Samples were collected from teeth diagnosed as chronic periodontics (PE), ulcerative pulpitis (PU), and retrograde pulpitis (RE). Genomic DNA was extracted. The quantitative polymerase chain reaction, targeting the 16S ribosomal RNA (rRNA), was adopted for the quantification of bacteria. Then, the V3-V4 hypervariable regions of the 16S rRNA gene were amplified and subjected to next-generation sequencing. The statistical analysis was performed by R software (V3.5.1)., Results: A total of 57 qualified samples were collected from 48 patients and analyzed (7 PE, 21 PU, and 19 RE). By linear discriminant analysis effect size, Kingella and Barnesiella were significantly increased in the periodontal pocket of retrograde pulpitis (RE-PE), compared with PE. The relative abundance of Clostridiales Incertae Sedis XI , Fusobacteriaceae , Fusobacterium , Parvimonas , Micrococcaceae , and Rothia was significantly increased in the pulp of retrograde pulpitis (RE-PU) than PU and RE-PE. Prevotella , Leptotrichia , Porphyromonas , Streptococcus , and Fusobacterium are consistently at a high abundance, across PU, RE-PE, and RE-PU., Conclusion: The current study highlighted the evidence that a specific microbial community is associated with the occurrence of retrograde pulpitis. The microenvironment of the root canal and pulp chamber will select microbiota. This study offered insights into the pathogenesis of retrograde pulpitis., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2021 Ping Sun et al.)

Leveraging systems biology approaches, we illustrate how metabolically distinct species of Clostridia protect against or worsen Clostridioides difficile infection in mice by modulating the pathogen's colonization, growth, and virulence to impact host survival. Gnotobiotic mice colonized with the amino acid fermenter Paraclostridium bifermentans survive infection with reduced disease severity, while mice colonized with the butyrate-producer, Clostridium sardiniense, succumb more rapidly. Systematic in vivo analyses revealed how each commensal alters the gut-nutrient environment to modulate the pathogen's metabolism, gene regulatory networks, and toxin production. Oral administration of P. bifermentans rescues conventional, clindamycin-treated mice from lethal C. difficile infection in a manner similar to that of monocolonized animals, thereby supporting the therapeutic potential of this commensal species. Our findings lay the foundation for mechanistically informed therapies to counter C. difficile disease using systems biology approaches to define host-commensal-pathogen interactions in vivo., Competing Interests: Declaration of interests L.B. and G.K.G. are co-inventors on patents for C. difficile microbiota therapeutics. L.B., G.K.G., and A.L.S. are SAB members and hold stock in ParetoBio. G.K.G.is an SAB member and holds stock in Kaleido, Inc. A.L.S. is a co-owner of ExArca Pharmaceuticals. The remaining authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Despite overall success, T cell checkpoint inhibitors for cancer treatment are still only efficient in a minority of patients. Recently, intestinal microbiota was found to critically modulate anti-cancer immunity and therapy response. Here, we identify Clostridiales members of the gut microbiota associated with a lower tumor burden in mouse models of colorectal cancer (CRC). Interestingly, these commensal species are also significantly reduced in CRC patients compared with healthy controls. Oral application of a mix of four Clostridiales strains (CC4) in mice prevented and even successfully treated CRC as stand-alone therapy. This effect depended on intratumoral infiltration and activation of CD8 + T cells. Single application of Roseburia intestinalis or Anaerostipes caccae was even more effective than CC4. In a direct comparison, the CC4 mix supplementation outperformed anti-PD-1 therapy in mouse models of CRC and melanoma. Our findings provide a strong preclinical foundation for exploring gut bacteria as novel stand-alone therapy against solid tumors., Competing Interests: Declaration of interests M.S. and M.R.S. have shares in PharmaBiome. M.S. served as Advisor for Gilead, Fresenius, Topadur, Takeda, and Celltrion, and received speaker’s honoraria from Falk Pharma and Vifor Pharma. T.W. and L. Berchtold are employees of PharmaBiome. G.E.L. is also an employee of PharmaBiome. G.R. is member of the Board of Directors of PharmaBiome. A patent related to this work has been generated (PCT/EP2021/053390). This intellectual property is entirely owned by the University of Zürich., (Copyright © 2021 Elsevier Inc. All rights reserved.)

We describe the anaerobic conversion of inositol stereoisomers to propionate and acetate by the abundant intestinal genus Anaerostipes. A inositol pathway was elucidated by nuclear magnetic resonance using [ 13 C]-inositols, mass spectrometry and proteogenomic analyses in A. rhamnosivorans, identifying 3-oxoacid CoA transferase as a key enzyme involved in both 3-oxopropionyl-CoA and propionate formation. This pathway also allowed conversion of phytate-derived inositol into propionate as shown with [ 13 C]-phytate in fecal samples amended with A. rhamnosivorans. Metabolic and (meta)genomic analyses explained the adaptation of Anaerostipes spp. to inositol-containing substrates and identified a propionate-production gene cluster to be inversely associated with metabolic biomarkers in (pre)diabetes cohorts. Co-administration of myo-inositol with live A. rhamnosivorans in western-diet fed mice reduced fasting-glucose levels comparing to heat-killed A. rhamnosivorans after 6-weeks treatment. Altogether, these data suggest a potential beneficial role for intestinal Anaerostipes spp. in promoting host health., (© 2021. The Author(s).)

The non-pathogenic intestinal microbes that conquer our intestines are not an accidental jumble of organisms, but rather a disparate community of microbes that coexist, and sustain a mutualistic and symbiotic relationship with the host. The gut microbiome has been shown to be influenced by animal physiology and vice versa. However, information is still scanty. The present study aimed to analyse the variation between faecal bacteria of three different stages (proestrus, estrus and postestrus) of the estrous cycle of Murrah buffalos. A phylogenetic study of buffalo faeces derived from three different stages of estrous cycle was conducted in order to compare the bacterial diversity among these three stages. We performed an exploratory microbiome analysis of buffalo faeces using 16S rRNA sequencing during these stages of the buffalo estrous cycle. A total of three bacterial phyla with six different bacterial orders and twenty-three different genera were identified among all the three comparative phases of the estrous cycle. Among them, the Clostridiales were found to be the most abundant, and Bacteroidales were present exclusive during the estrus phase. As faeces is a source of gut microbes and a non-invasive representative of the metabolic steroids and perceptible pheromones, the profiling of gut microbes during estrous cycle would provide clues towards the major microbes contributing to the perceptible pheromones during estrus stage. To the best of our knowledge, this is the first ever report describing the faecal bacterial diversity during estrous cycle of any ruminant species. Although future studies are required to understand the role of Clostridiales and Bacteroidales in faecal pheromone metabolism., Competing Interests: Declaration of Competing Interest The authors declare no conflict of research and financial interests., (Copyright © 2021 Society for Biology of Reproduction &the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.)

Lactate-driven chain elongation (LCE) has emerged as a new biotechnology to upgrade organic waste streams into a valuable biochemical and fuel precursor, medium - chain carboxylate, n -caproate. Considering that a low cost of downstream extraction is critical for biorefinery technology, a high concentration of n -caproate production is very important to improve the scale-up of the LCE process. We report here that in a nonsterile open environment, the n -caproate concentration was increased from the previous record of 25.7 g·liter -1 to a new high level of 33.7 g·liter -1 (76.8 g chemical oxygen demand [COD]·liter - 1 ), with the highest production rate being 11.5 g·liter -1 ·day -1 (26.2 g COD·liter - 1 ·day -1 ). In addition, the LCE process remained stable, with an average concentration of n -caproate production of 20.2 ± 5.62 g·liter -1 (46.1 ± 12.8 g COD·liter - 1 ) for 780 days. Dynamic changes in taxonomic composition integrated with metagenomic data reveal the microbial ecology for long-term production of high concentrations of n -caproate: (i) the core microbiome is related to efficient functional groups, such as Ruminococcaceae (with functional strain CPB6); (ii) the core bacteria can maintain stability for long-term operation; (iii) the microbial network has relatively low microbe-microbe interaction strength; and (iv) low relative abundance and variety of competitors. The network structure could be shaped by hydraulic retention time (HRT) over time, and long-term operation at an HRT of 8 days displayed higher efficacy. IMPORTANCE Our research revealed the microbial network of the LCE reactor microbiome for n- caproate production at high concentrations, which will provide a foundation for designing or engineering the LCE reactor microbiome to recover n -caproate from organic waste streams in the future. In addition, the hypothetical model of the reactor microbiome that we proposed may offer guidance for researchers to find the underlying microbial mechanism when they encounter low-efficiency n -caproate production from the LCE process. We anticipate that our research will rapidly advance LCE biotechnology with the goal of promoting the sustainable development of human society., (Copyright © 2021 American Society for Microbiology.)

Osteogenic endothelial progenitor cells (EPCs) contribute to impaired endothelial repair and promote coronary artery disease (CAD) and vascular calcification. Immature EPCs expressing osteocalcin (OCN) has been linked to unstable CAD; however, phenotypic regulation of OCN-expressing EPCs is not understood. We hypothesized that gut-microbiome derived pro-inflammatory substance, trimethylamine N-oxide (TMAO) might be associated with mobilization of OCN-expressing EPCs. This study aimed to investigate the association between dysbiosis, TMAO, and circulating mature and immature OCN-expressing EPCs levels in patients with and without CAD. We included 202 patients (CAD N = 88; no CAD N = 114) who underwent assessment of EPCs using flow cytometry and gut microbiome composition. Mature and immature EPCs co-staining for OCN were identified using cell surface markers as CD34+/CD133-/kinase insert domain receptor (KDR)+ and CD34-/CD133+/KDR+ cells, respectively. The number of observed operational taxonomy units (OTU), index of microbial richness, was used to identify patients with dysbiosis. The number of immature OCN-expressing EPCs were higher in patients with CAD or dysbiosis than patients without. TMAO levels were not associated with circulating levels of OCN-expressing EPCs. The relative abundance of Ruminococcus gnavus was moderately correlated with circulating levels of immature OCN-expressing EPCs, especially in diabetic patients. Gut dysbiosis was associated with increased levels of TMAO, immature OCN-expressing EPCs, and CAD. The relative abundance of Ruminococcus gnavus was correlated with immature OCN-expressing EPCs, suggesting that the harmful effects of immature OCN-expressing EPCs on CAD and potentially vascular calcification might be mediated by gut microbiome-derived systemic inflammation., Competing Interests: This study was sponsored by unrestricted grants from Sonomaceuticals, LLC, dba Whole-Vine Products (Santa Rosa, CA) and Mayo Clinic (Rochester, MN) to AL. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, and is characterized by the accumulation and presence of amyloid plaques (Aβ), tangles, dementia, and cognitive impairment. Currently, there is no known cure for AD; however, recently, the association between alteration of the gut microbiota and AD pathology has been explored to find novel therapeutic approaches. Microbiota-targeted intervention has been suggested as an attractive therapeutic approach for AD. Agathobaculum butyriciproducens (SR79) is a strict anaerobic and butyric acid-producing bacteria. We hypothesized that administration of SR79 might have a beneficial effect on cognitive deficits and AD pathologies. To determine the therapeutic effects of SR79 on AD pathologies, APP/PS1 transgenic and lipopolysaccharide -induced cognitive impairment mouse models were used. In the lipopolysaccharide -induced cognitive deficit model, the administration of SR79 improved cognitive function and decreased microglia activation. In addition, the administration of SR79 to APP/PS1 mice significantly improved novel object recognition and percent alteration results in novel object recognition and Y-maze alteration tests. Furthermore, Aβ plaque deposition and microglial activation were markedly reduced in the parietal cortex and hippocampus after SR79 treatment in APP/PS1 mice. SR79 treatment significantly decreased gene expression levels of IL-1β and C1QB and increased the gene expression levels of IGF-1 and thereby the downstream signaling pathway in the cortex of APP/PS1 mice. In conclusion, SR79 administration improved cognitive function and AD pathologies through the regulation of neuroinflammation and IGF-1 signaling in an animal model., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Blautia is a genus of anaerobic bacteria with probiotic characteristics that occur widely in the feces and intestines of mammals. Based on phenotypic and phylogenetic analyses, some species in the genera Clostridium and Ruminococcus have been reclassified as Blautia , so to date, there are 20 new species with valid published names in this genus. An extensive body of research has recently focused on the probiotic effects of this genus, such as biological transformation and its ability to regulate host health and alleviate metabolic syndrome. This article reviews the origin and biological characteristics of Blautia and the factors that affect its abundance and discusses its role in host health, thus laying a theoretical foundation for the development of new functional microorganisms with probiotic properties.

The early life microbiome plays critical roles in host development, shaping long-term outcomes including brain functioning. It is not known which initial infant colonizers elicit optimal neurodevelopment; thus, this study investigated the association between gut microbiome succession from the first week of life and head circumference growth (HCG), the earliest validated marker for neurodevelopment. Fecal samples were collected weekly from a preterm infant cohort during their neonatal intensive care unit stay and subjected to 16S rRNA gene sequencing for evaluating gut microbiome composition, in conjunction with clinical data and head circumference measurements. Preterm infants with suboptimal HCG trajectories had a depletion in the abundance/prevalence of Bacteroidota and Lachnospiraceae , independent of morbidity and caloric restriction. The severity of gut microbiome depletion matched the timing of significant HCG pattern separation between study groups at 30-week postmenstrual age demonstrating a potential mediating relationship resultant from clinical practices. Consideration of the clinical variables indicated that optimal infant microbiome succession is primarily driven by dispersal limitation (i.e., delivery mode) and secondarily by habitat filtering (i.e., antibiotics and enteral feeding). Bacteroidota and Lachnospiraceae are known core taxa of the adult microbiome, with roles in dietary glycan foraging, beneficial metabolite production and immunity, and our work provides evidence that their integration into the gut microbiome needs to occur early for optimal neurodevelopment.

Oscillospira is a class of organism that often appears in high-throughput sequencing data but has not been purely cultured and is widely present in the animal and human intestines. There is a strong association between variation in Oscillospira abundance and obesity, leanness, and human health. In addition, a growing body of studies has shown that Oscillospira is also implicated in other diseases, such as gallstones and chronic constipation, and has shown some correlation with the positive or negative changes in its course. Sequencing data combined with metabolic profiling indicate that Oscillospira is likely to be a genus capable of producing short-chain fatty acids (SCFAs) such as butyrate, which is an important reference indicator for screening "next-generation probiotics ". Considering the positive effects of Oscillospira in some specific diseases, such as obesity-related metabolic diseases, it has already been characterized as one of the next-generation probiotic candidates and therefore has great potential for development and application in the future food, health care, and biopharmaceutical products.

Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention., Competing Interests: The authors have declared that no competing interests exist.

Intestinal barrier leakage constitutes a potential therapeutic target for many inflammatory diseases and represents a disease progression marker during chronic viral infections. However, the causes of altered gut barrier remain mostly unknown. Using murine infection with lymphocytic choriomeningitis virus, we demonstrate that, in contrast to an acute viral strain, a persistent viral isolate leads to long-term viral replication in hematopoietic and mesenchymal cells, but not epithelial cells (IECs), in the intestine. Viral persistence drove sustained intestinal epithelial barrier leakage, which was characterized by increased paracellular flux of small molecules and was associated with enhanced colitis susceptibility. Type I IFN signaling caused tight junction dysregulation in IECs, promoted gut microbiome shifts and enhanced intestinal CD8 T cell responses. Notably, both type I IFN receptor blockade and CD8 T cell depletion prevented infection-induced barrier leakage. Our study demonstrates that infection with a virus that persistently replicates in the intestinal mucosa increases epithelial barrier permeability and reveals type I IFNs and CD8 T cells as causative factors of intestinal leakage during chronic infections., Competing Interests: Disclosures: R. Knight reported, "Biota Technology (salary/stock), Commence (consulting fee), Prometheus (consulting fee), CoreBiome (stock), GenCirq (stock), DayTwo (consulting fee), Cybele Microbiome (stock), BiomeSense (consulting fee), and IBM (grant)." No other disclosures were reported., (© 2020 Labarta-Bajo et al.)

A fascinating wealth of life cycles is observed in biology, from unicellularity to the concerted fragmentation of multicellular units. However, the understanding of factors driving their evolution is still limited. We show that costs of fragmentation have a major impact on the evolution of life cycles due to their influence on the growth rates of the associated populations. We model a group structured population of undifferentiated cells, where cell clusters reproduce by fragmentation. Fragmentation events are associated with a cost expressed by either a fragmentation delay, an additional risk, or a cell loss. The introduction of such fragmentation costs vastly increases the set of possible life cycles. Based on these findings, we suggest that the evolution of life cycles involving splitting into multiple offspring can be directly associated with the fragmentation cost. Moreover, the impact of this cost alone is strong enough to drive the emergence of multicellular units that eventually split into many single cells, even under scenarios that strongly disfavour collectives compared to solitary individuals., Competing Interests: The authors have declared that no competing interests exist.

A strictly anaerobic bacterial strain designated as SKVG24 was isolated from subgingival dental plaque samples of patients suffering from periodontitis. Cells were stained Gram-positive, rod shaped with endospore. The strain showed negative reaction to catalase and oxidase enzymes, but positive for gelatinase activity. Optimal growth was observed at 37 °C temperature and 7.0 pH. The 16S rRNA gene sequence BLAST analysis assigned strain SKVG24 to the genus Paraclostridium as it displayed 99.93% identity with P. benzoelyticum JC272 T followed by P. bifermentans ATCC 638 T (99.79%). However, average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) of the whole genome sequence showed <97% and <70% identity, respectively, with type strains of all closely related species. The G + C content of the DNA was 28.7 mol%. Total lipids profile showed presence of glycolipids as major lipids. Pathogenic features like hemolysis, gelatin hydrolysis and production of volatile sulfur compounds exhibited by strain SKVG24 T were analogous to those observed in the established oral pathogenic strains. Further, whole genome sequence analysis confirmed the presence of genes encoding virulence factors and provided genomic insights on adaptation of the strain in oral environment. Based on the phenotypic and genetic differences with phylogenetic relatives, strain SKVG24 T is proposed to represent a new species of the genus Paraclostridium with potential pathogenic ability, for which the name Paraclostridium dentum sp. nov., is suggested. The proposed type strain is SKVG24 T (MTCC 12836 T ; = JCM 32760 T )., Competing Interests: Declaration of competing interest All authors of this manuscript declare no conflict of interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Chikungunya virus (CHIKV), an emerging alphavirus, has infected millions of people. However, the factors modulating disease outcome remain poorly understood. Here, we show in germ-free mice or in oral antibiotic-treated conventionally housed mice with depleted intestinal microbiomes that greater CHIKV infection and spread occurs within 1 day of virus inoculation. Alteration of the microbiome alters TLR7-MyD88 signaling in plasmacytoid dendritic cells (pDCs) and blunts systemic production of type I interferon (IFN). Consequently, circulating monocytes express fewer IFN-stimulated genes and become permissive for CHIKV infection. Reconstitution with a single bacterial species, Clostridium scindens, or its derived metabolite, the secondary bile acid deoxycholic acid, can restore pDC- and MyD88-dependent type I IFN responses to restrict systemic CHIKV infection and transmission back to vector mosquitoes. Thus, symbiotic intestinal bacteria modulate antiviral immunity and levels of circulating alphaviruses within hours of infection through a bile acid-pDC-IFN signaling axis, which affects viremia, dissemination, and potentially transmission., Competing Interests: Declaration of Interests M.S.D. is a consultant for Inbios, Eli Lilly, Vir Biotechnology, NGM Biopharmaceuticals, and on the Scientific Advisory Board of Moderna. The Diamond laboratory has received unrelated funding under sponsored research agreements from Moderna and Emergent BioSolutions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We investigated the requirement of 15 human butyrate-producing gut bacterial strains for eight B vitamins and the proteinogenic amino acids by a combination of genome sequence analysis and in vitro growth experiments. The Ruminococcaceae species Faecalibacterium prausnitzii and Subdoligranulum variabile were auxotrophic for most of the vitamins and the amino acid tryptophan. Within the Lachnospiraceae , most species were prototrophic for all amino acids and several vitamins, but biotin auxotrophy was widespread. In addition, most of the strains belonging to Eubacterium rectale and Roseburia spp., but few of the other Lachnospiraceae strains, were auxotrophic for thiamine and folate. Synthetic coculture experiments of five thiamine or folate auxotrophic strains with different prototrophic bacteria in the absence and presence of different vitamin concentrations were carried out. This demonstrated that cross-feeding between bacteria does take place and revealed differences in cross-feeding efficiency between prototrophic strains. Vitamin-independent growth stimulation in coculture compared to monococulture was also observed, in particular for F. prausnitzii A2-165, suggesting that it benefits from the provision of other growth factors from community members. The presence of multiple vitamin auxotrophies in the most abundant butyrate-producing Firmicutes species found in the healthy human colon indicates that these bacteria depend upon vitamins supplied from the diet or via cross-feeding from other members of the microbial community. IMPORTANCE Microbes in the intestinal tract have a strong influence on human health. Their fermentation of dietary nondigestible carbohydrates leads to the formation of health-promoting short-chain fatty acids, including butyrate, which is the main fuel for the colonic wall and has anticarcinogenic and anti-inflammatory properties. A good understanding of the growth requirements of butyrate-producing bacteria is important for the development of efficient strategies to promote these microbes in the gut, especially in cases where their abundance is altered. The demonstration of the inability of several dominant butyrate producers to grow in the absence of certain vitamins confirms the results of previous in silico analyses. Furthermore, establishing that strains prototrophic for thiamine or folate (butyrate producers and non-butyrate producers) were able to stimulate growth and affect the composition of auxotrophic synthetic communities suggests that the provision of prototrophic bacteria that are efficient cross feeders may stimulate butyrate-producing bacteria under certain in vivo conditions., (Copyright © 2020 Soto-Martin et al.)

Rapeseed meal is a sustainable feed ingredient that can be used as an alternative to imported soybean meal in European pig production. The gut microbiota plays an important role on pig physiology and health but the impact on microbiota of using rapeseed in diets is still not well known. In this study, 84 purebred Norwegian Landrace pigs with average initial weight of 25 kg were divided into two groups and fed for approximately three months with either a control diet containing soybean meal (CON) or a high-fiber experimental diet where 20% rapeseed meal (RSF) was included as an alternative to soybean meal in CON. The composition and function of microbiome in gut digesta samples were analyzed by performing 16S rRNA gene sequencing and culturing of bacteria. The microbiota diversity and composition were similar between the dietary treatments; however, relative abundance of a variety of bacterial groups and imputed functions of microbiome in the ileum and large intestine were altered when the pigs were fed with a rapeseed-based diet. It was notable that the immune-inducing bacterial group Mucispirillum and anti-inflammatory stimulating bacteria Lachnospira were more abundant in the ileum and large intestine of the RSF group, respectively. Moreover, there was a higher abundance of major amino acid fermenters and amylolytic bacteria in the CON group and a high abundance of putative short chain fatty acid producers in RSF group. In comparison with the CON group, the gut microbiome of RSF group possessed an enhanced potential for carbohydrate and energy metabolism and a reduced potential for bacterial pathogenicity-related pathways.

Oscillospira is a common yet rarely cultivated gut bacterial genus. Recently human gut microbiota studies have demonstrated its underlying significance for host health. However, little is known about Oscillospira-related host information and the links between Oscillospira and other members of the gut microbial community. To study the ecology of Oscillospira and gain insights into Oscillospira-related host physiological conditions, we analyzed data from the Guangdong Gut Microbiome Project, one of the largest gut microbiota database currently. Data of 6376 participants were analyzed. We studied the prevalence and relative abundance of Oscillospira as well as the profiles of associated microbial communities. We found that Oscillospira is closely related to human health because its abundance was positively correlated with microbial diversity, high density lipoprotein, and sleep time, and was inversely correlated with diastolic blood pressure, systolic blood pressure, fasting blood glucose, triglyceride, uric acid and Bristol stool type. Moreover, random forest analysis with five-fold cross validation showed Oscillospira could be a predictor of low BMI and constipation in the subset. Overall, in this study, we provide a basic understanding of Oscillospira-related microbiota profile and physiological parameters of the host. Our results indicate Oscillospira may play a role in aggravating constipation.

Filifactor alocis, a Gram-positive anaerobic bacterium, is now a proposed diagnostic indicator of periodontal disease. Because the stress response of this bacterium to the oxidative environment of the periodontal pocket may impact its pathogenicity, an understanding of its oxidative stress resistance strategy is vital. Interrogation of the F. alocis genome identified the HMPREF0389&#95;00796 gene that encodes for a putative superoxide reductase (SOR) enzyme. SORs are non-heme, iron-containing enzymes that can catalyze the reduction of superoxide radicals to hydrogen peroxide and are important in the protection against oxidative stress. In this study, we have functionally characterized the putative SOR (FA796) from F. alocis ATCC 35896. The recombinant FA796 protein, which is predicted to be a homotetramer of the 1Fe-SOR class, can reduce superoxide radicals. F. alocis FLL141 (∆FA796::ermF) was significantly more sensitive to oxygen/air exposure compared to the parent strain. Sensitivity correlated with the level of intracellular superoxide radicals. Additionally, the FA796-defective mutant had increased sensitivity to hydrogen peroxide-induced stress, was inhibited in its ability to form biofilm and had reduced survival in epithelial cells. Collectively, these results suggest that the F. alocis SOR protein is a key enzymatic scavenger of superoxide radicals and protects the bacterium from oxidative stress conditions.

Objectives: Periodontitis is a highly prevalent chronic inflammatory disease caused by periodontopathogens, such as Filifactor alocis. This study sought to examine the matrix metalloproteinase (MMP)-1 synthesis by monocytic and fibroblastic cells in response to F. alocis and to unravel the underlying cellular mechanisms., Material and Methods: Gingival biopsies from periodontally healthy and periodontitis individuals were analyzed for the presence of F. alocis and MMP-1 by RT-PCR. Human gingival fibroblastic (HGF-1) and monocytic (THP-1) cells were stimulated with F. alocis in the presence and absence of a blocking toll-like receptor (TLR)2 antibody or specific inhibitors against MAPKs. MMP-1 expression and protein levels were studied by RT-PCR and ELISA, respectively., Results: F. alocis was highly prevalent in biopsies from periodontitis patients but barely present in the healthy gingiva. Significantly higher MMP-1 expression levels were found in the inflamed gingiva as compared with healthy biopsies. F. alocis caused a significant and dose-dependent MMP-1 upregulation in both cells. The stimulatory effect of F. alocis on MMP-1 was TLR2- and MAPK-dependent and more pronounced on THP-1 cells as compared with HGF-1 cells., Conclusions: Our results demonstrate that F. alocis and MMP-1 are more prevalent at periodontitis sites. Additionally, our study provides original evidence that F. alocis can stimulate MMP-1 production by fibroblastic and monocytic cells, suggesting that F. alocis may contribute to periodontal breakdown through MMP-1., Clinical Relevance: F. alocis and MMP-1 are linked to each other and key players in periodontitis, which may have significant implications for future diagnostic and treatment strategies.

Clostridioides difficile is one of the leading causes of antibiotic-associated diarrhea. Gut microbiota-derived secondary bile acids and commensal Clostridia that carry the bile acid-inducible ( bai ) operon are associated with protection from C. difficile infection (CDI), although the mechanism is not known. In this study, we hypothesized that commensal Clostridia are important for providing colonization resistance against C. difficile due to their ability to produce secondary bile acids, as well as potentially competing against C. difficile for similar nutrients. To test this hypothesis, we examined the abilities of four commensal Clostridia carrying the bai operon ( Clostridium scindens VPI 12708, C. scindens ATCC 35704, Clostridium hiranonis , and Clostridium hylemonae ) to convert cholate (CA) to deoxycholate (DCA) in vitro, and we determined whether the amount of DCA produced was sufficient to inhibit the growth of a clinically relevant C. difficile strain. We also investigated the competitive relationships between these commensals and C. difficile using an in vitro coculture system. We found that inhibition of C. difficile growth by commensal Clostridia supplemented with CA was strain dependent, correlated with the production of ∼2 mM DCA, and increased the expression of bai operon genes. We also found that C. difficile was able to outcompete all four commensal Clostridia in an in vitro coculture system. These studies are instrumental in understanding the relationship between commensal Clostridia and C. difficile in the gut, which is vital for designing targeted bacterial therapeutics. Future studies dissecting the regulation of the bai operon in vitro and in vivo and how this affects CDI will be important. IMPORTANCE Commensal Clostridia carrying the bai operon, such as C. scindens, have been associated with protection against CDI; however, the mechanism for this protection is unknown. Herein, we show four commensal Clostridia that carry the bai operon and affect C. difficile growth in a strain-dependent manner, with and without the addition of cholate. Inhibition of C. difficile by commensals correlated with the efficient conversion of cholate to deoxycholate, a secondary bile acid that inhibits C. difficile germination, growth, and toxin production. Competition studies also revealed that C. difficile was able to outcompete the commensals in an in vitro coculture system. These studies are instrumental in understanding the relationship between commensal Clostridia and C. difficile in the gut, which is vital for designing targeted bacterial therapeutics., (Copyright © 2020 American Society for Microbiology.)

Three large (2084-, 984-, and 2104-amino acids) endo-α-N-acetylgalactosaminidase candidate genes from the commensal human gut bacterium Tyzzerella nexilis were successfully cloned and subsequently expressed in Escherichia coli. Activity tests of the purified proteins revealed that two of the candidate genes (Tn0153 and Tn2105) were able to hydrolyze the disaccharide unit from Galβ1-3GalNAc-α-pNP. The biochemical characterization revealed optimum pH conditions of 4.0 for both enzymes and temperature optima of 50 °C. The addition of 2-mercaptoethanol, Triton X-100 and urea had only minor effects on the activity of the enzymes, and the addition of imidazole and sodium dodecyl sulfate led to a significant reduction of the enzymes' activities. A mutational study identified and confirmed the role of the catalytically significant amino acids. The present study describes the first functional characterization of members of the GH101 family from this human gut symbiont., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Dysbiosis of the intestinal microbiota has been implicated in insulin resistance, although evidence regarding causality in humans is scarce. We performed a phase I/II dose-finding and safety study on the effect of oral intake of the anaerobic butyrogenic strain Anaerobutyricum soehngenii on glucose metabolism in 24 subjects with metabolic syndrome. We found that treatment with A. soehngenii was safe and observed a significant correlation between the measured fecal abundance of administered A. soehngenii and improvement in peripheral insulin sensitivity after 4 weeks of treatment. This was accompanied by an altered microbiota composition and a change in bile acid metabolism. Finally, we show that metabolic response upon administration of A. soehngenii (defined as improved insulin sensitivity 4 weeks after A. soehngenii intake) is dependent on microbiota composition at baseline. These data in humans are promising, but additional studies are needed to reproduce our findings and to investigate long-term effects, as well as other modes of delivery.

Members of the gut microbiota are thought to experience strong competition for nutrients. However, how such competition shapes their evolutionary dynamics and depends on intra- and interspecies interactions is poorly understood. Here, we test the hypothesis that Escherichia coli evolution in the mouse gut is more predictable across hosts in the absence of interspecies competition than in the presence of other microbial species. In support, we observed that lrp, a gene encoding a global regulator of amino acid metabolism, was repeatedly selected in germ-free mice 2 weeks after mono-colonization by this bacterium. We established that this specific genetic adaptation increased E. coli's ability to compete for amino acids, and analysis of gut metabolites identified serine and threonine as the metabolites preferentially consumed by E. coli in the mono-colonized mouse gut. Preference for serine consumption was further supported by testing a set of mutants that showed loss of advantage of an lrp mutant impaired in serine metabolism in vitro and in vivo. Remarkably, the presence of a single additional member of the microbiota, Blautia coccoides, was sufficient to alter the gut metabolome and, consequently, the evolutionary path of E. coli. In this environment, the fitness advantage of the lrp mutant bacteria is lost, and mutations in genes involved in anaerobic respiration were selected instead, recapitulating the eco-evolutionary context from mice with a complex microbiota. Together, these results highlight the metabolic plasticity and evolutionary versatility of E. coli, tailored to the specific ecology it experiences in the gut., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Clostridia can cause hepatic damage in domestic livestock, and wild and laboratory animals. Clostridium novyi type B causes infectious necrotic hepatitis (INH) in sheep and less frequently in other species. Spores of C. novyi type B can be present in soil; after ingestion, they reach the liver via portal circulation where they persist in phagocytic cells. Following liver damage, frequently caused by migrating parasites, local anaerobic conditions allow germination of the clostridial spores and production of toxins. C. novyi type B alpha toxin causes necrotizing hepatitis and extensive edema, congestion, and hemorrhage in multiple organs. Clostridium haemolyticum causes bacillary hemoglobinuria (BH) in cattle, sheep, and rarely, horses. Beta toxin is the main virulence factor of C. haemolyticum , causing hepatic necrosis and hemolysis. Clostridium piliforme , the causal agent of Tyzzer disease (TD), is the only gram-negative and obligate intracellular pathogenic clostridia. TD occurs in multiple species, but it is more frequent in foals, lagomorphs, and laboratory animals. The mode of transmission is fecal-oral, with ingestion of spores from a fecal-contaminated environment. In affected animals, C. piliforme proliferates in the intestinal mucosa, resulting in necrosis, and then disseminates to the liver and other organs. Virulence factors for this microorganism have not been identified, to date. Given the peracute or acute nature of clostridial hepatitis in animals, treatment is rarely effective. However, INH and BH can be prevented, and should be controlled by vaccination and control of liver flukes. To date, no vaccine is available to prevent TD.

Background and Objectives: Recent evidence suggests that oral bacteria can affect extra-oral diseases by modulating aspects of the gut environment such as the microbiome, metabolome, and immune profiles. However, differences in the effects of different types of oral bacteria, particularly periodontopathic and health-associated bacteria, remain elusive., Materials and Methods: Five-week-old germ-free mice were orally administered with either periodontopathic bacteria as oral pathobionts (Porphyromonas gingivalis, Filifactor alocis, and Fusobacterium nucleatum) or bacteria associated with periodontal health (Actinomyces naeslundii, Streptococcus mitis, and Veillonella rogosae) twice a week for five weeks. The presence of all bacterial species in the feces and the livers of the mice was analyzed via polymerase chain reaction (PCR), using specific primers for 16S rRNA genes. Alveolar bone resorption was evaluated histologically. The expression profiles of various genes in the liver and small intestine were analyzed using real-time PCR. Sera were analyzed to determine the levels of antibodies and endotoxin. The proportions of T helper 17 (Th17) and regulatory T (Treg) cells in mesenteric lymph nodes and Peyer's patches were analyzed using flow cytometry., Results: Neither of the types of bacteria administered in this experiment induced alveolar bone resorption. All bacteria elicited some degree of systemic antibody response in the mice, although the response to S. mitis was not obvious. The response to P. gingivalis and V. rogosae was strongest. Generally, the health-associated bacteria but not the periodontitis-associated bacteria were detected in fecal samples. Interestingly, only Fusobacterium nucleatum DNA was detected in the liver, despite that live Fusobacterium nucleatum were not detected in the liver. The levels of interleukin-17 in the intestine and genes related to lipid accumulation in the liver were significantly higher in the mice that received periodontitis-associated bacteria. In addition, expression of the gene associated with endoplasmic reticulum stress was higher and that of the gene controlling circadian rhythm was lower in the periodontitis group. There was no difference in serum endotoxin, T-cell phenotypes in the lymphatic tissues, or genes related to the gut barrier., Conclusion: Oral administration of periodontitis-associated bacteria can induce pathological changes in the liver and intestine that are implicated in the process of periodontitis. These findings further support the importance of the oral-gut connection., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The bacterium Flavonifractor plautii (FP), which is found in human feces, has been reported to participate in catechin metabolism in the gut, but this bacterium's effects on immune function are unclear. We assessed the effect of oral administration of FP on the immune response in ovalbumin (OVA) -sensitized mice. We demonstrated that the FP treatment suppressed interleukin (IL)-4 in splenocytes and OVA-specific IgE production in serum from OVA-sensitized mice. Moreover, oral administration of FP augmented CD4 + CD25 + T cells and CD103 + CD11c + DCs. In animals of the FP group, the proportion of FP was increased in the mesenteric lymph nodes (MLNs), as was the proportion of Deferribacteres in the cecum. Oral administration of FP may inhibit the Th2 immune response by incorporation into the MLNs and/or by inducing changes in the gut microbiota. Thus, FP may be useful in alleviating antigen-induced Th2 immune responses., (Copyright © 2020 Ogita, Yamamoto, Mikami, Shigemori, Sato and Shimosato.)

The intestinal microbiota plays an essential role in the metabolism and immune competence of chickens from the first day after hatching. In modern production systems, chicks are isolated from adult chickens, instead hatching in a clean environment. As a result, chicks are colonized by environmental bacteria, including potential pathogens. There is a need to investigate methods by which chicks can be exposed to a more appropriate microbial community at hatching. Such methods must be easy to apply in a hatchery and produce consistent results. The development of the intestinal microbiota of chicks hatched from eggs sprayed with dilute adult cecal content during incubation was observed at 0, 3, 7, and 14 days posthatching (dph) across two experiments. High-throughput Illumina sequencing was performed for the V4 hypervariable region of the 16S rRNA gene. A topical treatment of dilute adult cecal content was sufficient to transplant spore-forming bacteria such as Lachnospiraceae and Ruminococcaceae However, this treatment was not able to transplant other taxa that are considered to be core elements of the chicken cecal microbiota, such as Bacteroidaceae , Lactobacillaceae , Bifidobacteriaceae , and Burkholderiaceae The topical treatment significantly altered the microbiota of chicks immediately posthatching and accelerated the normal development of the microbiota with earlier colonization by Ruminococcaceae in the cecum and "Candidatus Arthromitus " in the ileum. The effect of the treatment on the cecal microbiota was maximal at 3 dph but diminished over time. IMPORTANCE Over the last 60 years poultry production has intensified in response to increased demand for meat. In modern systems, chicks hatch without contacting chickens and their gut bacteria. Consequently, they are colonized by environmental bacteria that may cause disease. The normal bacteria that live in the gut, or intestinal microbiota, play an important role in the development of the immune system. Therefore, it is essential to find easy ways to expose chicks to the more appropriate bacteria at hatching. This experiment investigated whether spraying eggs with adult cecal contents was sufficient to transfer an adult microbiota to chicks. Our findings show that spore-forming bacteria were transplanted, but other members of the microbiota were not. In this respect, the spray application was partially successful, but the timing of the spray needs to be modified to ensure that more bacteria are transferred., (Copyright © 2020 Richards-Rios et al.)

In our search for novel anaerobes with potential carbohydrate polymers degrading activity, we have isolated a xylan-degrading bacterial strain SYSU GA17129 T from an anammox bacteria dominant wastewater treatment plant. Phylogenetic analysis of the 16S rRNA gene sequence indicated the strain SYSU GA17129 T belong to the order Clostridiales and shared highest sequence identity with Caldicoprobacter faecalis DSM 20678 T (89.9%). The strain was thermophilic, obligately anaerobic, non-motile and rod shaped. Optimum growth of the strain was observed at 45 °C, pH 8.0 and in the presence of 0.5% NaCl (w/v). The chemotaxonomic features of the strain SYSU GA17129 T comprised of C 14:0 FAME, iso-C 15:0 FAME and C 16:0 FAME as the major fatty acids (>10%), diphosphatidylglycerol, phosphatidylinositol mannoside, an unidentified phospholipid, three unidentified polar lipids and two unidentified glycolipids as its polar lipids, and meso-diaminopimelic acid (meso-DAP) as the diamino acid in peptidoglycan. The G + C content of the genomic DNA was 35.9%. The strain could be distinguished from other defined families within the order Clostridiales by the differences in phenotypic and physiological characteristics, distinct phylogenetic lineage in 16S rRNA gene- and genome-based phylogenies and low genomic relatedness index. Based on these distinguishing properties, strain SYSU GA17129 T is proposed to represent a new species of a new genus Xylanivirga thermophila gen. nov., sp. nov., within a new family Xylanivirgaceae fam. nov. The type species of the new taxon is SYSU GA17129 T (=KCTC 15754 T  = CGMCC 1.5282 T ). This strain is characterized within the order Clostridiales, class Clostridia of the phylum Firmicutes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Acetoanaerobium sticklandii DSM 519 is a hyper-ammonia producing anaerobic bacterium that can be able utilizes amino acids as sole carbon and energy sources for its growth and energetic metabolism. A lack of knowledge on its molecular machinery and 30.5% conserved hypothetical proteins (HPs; operome) hinders the successful utility in biofuel applications. In this study, we have predicted, characterized and categorized its operome whose functions are still not determined accurately using a combined bioinformatics approach. The functions of 64 of the 359 predicted HPs are involved in diverse metabolic subsystems. A. sticklandii operome has consisted of 16% Rossmann fold and 46% miscellaneous folds. Subsystems-based technology has classified 51 HPs contributing to the small-molecular reactions, 26 in macromolecular reactions and 12 in the biosynthesis of cofactors, prosthetic groups and electron carriers. A generality of functions predicted from its operome contributed to the cell cycle, amino acid metabolism, membrane transport, and regulatory processes. Many of them have duplicated functions as paralogs in this genome. A. sticklandii has the ability to compete with invading microorganisms and tolerate abiotic stresses, which can be overwhelmed by the predicted functions of its operome. Results of this study revealed that it has specialized systems for amino acid catabolism-directed solventogenesis and acidogenesis but the level of gene expression may determine the metabolic function in amino acid fermenting niches in the rumina of cattle. As shown by our analysis, the predicted functions of its operome allow us for a better understanding of the growth and physiology at systems-scale., (Copyright © 2019. Published by Elsevier Ltd.)

A strictly anaerobic bacterium, designated as strain KGMB-03357 T , was isolated from the faeces of a healthy Korean selected by Bundang Seoul National University based on health status. Cells of strain KGMB03357 T are Gram-stain-positive, non-motile, non-spore-forming, and observed as straight or curved rods. The isolate grew at 10-45°C (optimum temperature of 40°C) and a pH range of 5.1-10.5 (optimum pH of 6.8). Analysis of phylogenetic trees based on the 16S rRNA gene sequences revealed that strain KGMB03357 T forms a lineage within the genus Anaerotignum, and is most closely related to Anaerotignum lactatifermentans G17 T (= KCTC 15066 T , 96.1%), Anaerotignum propionicum DSM 1682T (= KCTC 5582 T , 94.9%), Anaerotignum neopropionicum DSM 03847 T (= KCTC 15564T, 94.9%), and Anaerotignum aminivorans SH021 T (= KCTC 15705T, 94.8%). The ANI values between strain KGMB 03357T and members of the genus Anaerotignum were 73.3-71.0%, which are below the ANI criterion for interspecies identity. The DNA G + C content based on the whole-genome sequence is 47.3 mol%. The major cellular fatty acids of strain KGMB03357 T are C 16:0 , C 18:0 , C 18∶1 cis 9, and anteiso-C 15∶0 . Strain KGMB03357T contains meso-diaminopimelic acid as the diagnostic amino acid in the cell wall peptidoglycan. Based on the phenotypic, phylogenetic, and genomic properties, strain KGMB 03357 T represents a novel species of the genus Anaerotignum, for which the name Anaerotignum faecicola sp. nov. is proposed. The type strain is KGMB03357 T (= KCTC 15736T = DSM 107953 T ).

The Christensenellaceae, a recently described family in the phylum Firmicutes, is emerging as an important player in human health. The relative abundance of Christensenellaceae in the human gut is inversely related to host body mass index (BMI) in different populations and multiple studies, making its relationship with BMI the most robust and reproducible link between the microbial ecology of the human gut and metabolic disease reported to date. The family is also related to a healthy status in a number of other different disease contexts, including obesity and inflammatory bowel disease. In addition, Christensenellaceae is highly heritable across multiple populations, although specific human genes underlying its heritability have so far been elusive. Further research into the microbial ecology and metabolism of these bacteria should reveal mechanistic underpinnings of their host-health associations and enable their development as therapeutics.

A novel Gram-stain-positive, obligately anaerobic, spore-forming rod, designated strain ChDC B114 T , was isolated from a human dental plaque of a gingivitis lesion. The strain was characterized by polyphasic taxonomic analysis to identify it at the species level. The 16S ribosomal RNA gene (16S rDNA) sequence analysis revealed that the strain belongs to the genus Lachnoanaerobaculum. The percent similarity of the 16S rDNA of the strain was closest to the homologous gene sequence of Lachnoanaerobaculum orale N1 T (98.5%) and Lachnoanaerobaculum saburreum CCUG 28089 T (97.6%). The major fatty acids of strain ChDC B114 T were C 16:0 (30.7%), C 14:0 (17.7%), iso-C 19:0 (14.9%), and C 17:0 2OH (12.0%). The draft genome of strain ChDC B114 T was 3,097,953 bp in length. The G+C content of the strain was 35.9 mol %. Average nucleotide identity values between strain ChDC B114 T and L. orale N1 T and L. saburreum CCUG 28089 T were 83.2% and 82.0%, respectively. Genome-to-genome distance values between strain ChDC B114 T and L. orale N1 T and L. saburreum CCUG 28089 T were 26.8% (24.5-29.3%) and 26.30% (24.0-28.8%), respectively. Based on these results, strain ChDC B114 T (= KCOM 2030 T  = JCM 33452 T ) should be classified as a novel species of genus Lachnoanaerobaculum, for which the name Lachnoanaerobaculum gingivalis sp. nov. is proposed.

The homeostasis process in the gut tissue of humans relies on intestinal bacteria. However, the intestine is a complex structural tissue with a huge superficial area, and thus the effective application of probiotics in the treatment of Crohn's disease (CD) is still challenging. Herein, we show the feasibility of probiotic target delivery and retention using magnetic iron oxide nanoparticle-internalized Roseburia intestinalis, which can be easily directed by a magnetic field in vitro and in vivo. Subsequently, the increased colonization of this core profitable flora not only resulted in a better therapy effect than traditional intragastric administration but also altered the bacterial composition, leading to a higher diversity in microbial taxa in rats with colitis. Our findings illustrate the exciting opportunities that nanotechnology offers for alternative strategies to modulate biological systems remotely and precisely, which represent a step towards the wireless magnetic manipulation of living biological entities in microbiology.

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), has a complex etiology that may be associated with dysbiosis of the microbiota. Previously, our study revealed significant loss of Roseburia intestinalis from the gut of untreated patients with CD, and that R. intestinalis exerted anti‑inflammatory functions in TNBS‑induced colitis; however, the function of R. intestinalis supernatant is unknown. Therefore, LPS‑induced macrophages, including RAW264.7 macrophages and bone marrow‑derived macrophages were treated with R. intestinalis supernatant. The results indicated that R. intestinalis supernatant suppressed expression of interleukin (IL)‑6 and signal transducer and activator of transcription 3 (STAT3) by macrophages. Additionally, these findings were further verified in vivo in DSS‑ and TNBS‑induced mouse models of colitis. It was observed that R. intestinalis supernatant ameliorated IBD colitis by reducing the number of inflammatory macrophages and Th17 cells in the colon, and by downregulating the expression of IL‑6 and STAT3. Finally, the non‑protein components of R. intestinalis supernatant were examined using gas chromatography‑mass spectrometry analysis and identified the presence of short‑chain fatty acids. In conclusion, the results of the present study indicated that R. intestinalis supernatant may regulate immune responses and ameliorate colitis.

Objective: Levels of oncostatin M (OSM) and the composition of gut microbiota predict responses to anti-TNF agents used for IBD therapy. Here, the aim was to investigate the effects of Roseburia intestinalis , a gut microbiota, on OSM and on intestinal barrier in colitis. Methods: In the murine model of 3% dextran sulfate sodium (DSS)-induced colitis, we tested disease activity index (DAI), colon length, histological score and expression of tight junction (TJ) proteins (ZO-1, occludin and claudin-1), OSM, TNF-α and TLR5. In addition, a cellular model was used to examine the role of R. intestinalis during secretion of OSM by lipopolysaccharide (LPS)-induced bone marrow-derived macrophages (BMDMs) isolated from wild-type (WT) and TLR5 knockout (TLR5 KO) mice. Furthermore, we evaluated the impact of OSM on expressions of TJ proteins by Caco-2 cells. Results: R. intestinalis in DSS-induced colitis decreased DAI score ( p  < .001), colon length shortening (6.46 ± 0.36 cm vs 5.65 ± 0.47 cm, p  = .022), histological score (2.667 ± 1.15 vs 5.33 ± 1.14, p  = .018) and increased expression of TJ proteins ( p  < .05). In addition, R. intestinalis reduced expression of OSM ( p  < .05) and TNF-α ( p  < .05), while increasing expression of TLR5 ( p  < .05). Furthermore, R. intestinalis reduced secretion of OSM ( p  < .05) by LPS-induced BMDMs isolated from WT and TLR5 KO mice. Moreover, OSM downregulated expression of TJ proteins ( p  < .05) by Caco-2 cells in a concentration-dependent manner. Conclusions: These results indicate that R. intestinalis attenuates inflammation in IBD by decreasing secretion of OSM and by promoting intestinal barrier function. Taken together, the data provide insight into the role of the gut microbiota in patients with IBD who are resistant to anti-TNF therapy.

The ruminal bacteria Pseudobutyrivibrio xylanivorans strain 2 (P. xylanivorans 2), that mediates the digestion of plant fiber, is considered an attractive candidate for probiotics. Adherence to the epithelium of the digestive tract of the host is one of the major requirements for probiotics. In this study, we assessed the adhesion of P. xylanivorans 2 to SW480 cells and characterized this process utilizing multiple microscopy approaches. Our results indicate that a multiplicity of infection of 200 CFU/cell allows the highest bacteria to cell binding ratio, with a lower percentage of auto-agglutination events. The comparison of the adherence capacity subjected heat-shock treatment (100 °C, 1 min), which produces the denaturalization of proteins at the bacterial surface, as opposed untreated P. xylanivorans, suggested that this bacteria may attach to SW480 cells utilizing a proteinaceous structure. Confocal microscopy analyses indicate that P. xylanivorans 2 attachment induces the formation of F-actin-enriched areas on the surface of SW480 cells. Transmission electron microscopy (TEM) revealed the formation of a structure similar to a pedestal in the area of the epithelial cell surface, where the bacterium rests. Finally, a casual finding of TEM analysis of transverse and longitudinal thin-sections of P. xylanivorans 2, revealed irregular intra-cytoplasmic structures compatibles with the so-called bacterial microcompartments. This is the first ultrastructural description of bacterial microcompartments-like structures in the genus Pseudobutyrivibrio., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Taxonomic studies of strain PAGU 1678 T , an obligately anaerobic, gram-positive, spore-forming bacterium isolated from biobreeding rat feces, were performed. This strain has been demonstrated to have the ability to exacerbate pathosis in a mouse model of dextran sulfate sodium-induced ulcerative colitis. Phylogenetic analysis based on the 16S rRNA gene showed high homology with Paraclostridium bifermentans. To clarify the correct taxonomic position of strain PAGU 1678 T , a comparative taxonomic study using P. bifermentans PAGU 2008 T (═JCM 1386 T ) and the closely related bacterial species P. benzoelyticum PAGU 2068 T (═LMG 28745 T ) was carried out. Despite the close similarity of 16S rRNA gene sequences, DNA-DNA hybridization between strain PAGU 1678 T and P. bifermentans PAGU 2008 T was 60.03% on average, average nucleotide identity was 96.17%, and it was shown to have different genomic sequences. Biochemically, strain PAGU 1678 T could be differentiated from P. bifermentans PAGU 2008 T by H 2 S production. Furthermore, strain PAGU 1678 T was characterized by the presence of two phospholipids with different polarity on polar lipid analysis. In addition, strain PAGU 1678 T differed from P. bifermentans PAGU 2008 T in findings on whole-cell protein analysis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. On the basis of these biochemical and genetic characteristics, a novel subspecies of P. bifermentans with the name Paraclostridium bifermentans subsp. muricolitidis subsp. nov. is here proposed, with PAGU 1678 T (═CCUG 72489 T ═NBRC 113386 T ) as the type strain, which automatically creates P. bifermentans subsp. bifermentans subsp. nov. JCM 1386 T (═ATCC 638 T ═DSM 14991 T )., (© 2018 The Societies and John Wiley & Sons Australia, Ltd.)

Intestinimonas massiliensis sp. nov strain GD2 T is a new species of the genus Intestinimonas (the second, following Intestinimonas butyriciproducens gen. nov., sp. nov). First isolated from the gut microbiota of a healthy subject of French origin using a culturomics approach combined with taxono-genomics, it is strictly anaerobic, nonspore-forming, rod-shaped, with catalase- and oxidase-negative reactions. Its growth was observed after preincubation in an anaerobic blood culture enriched with sheep blood (5%) and rumen fluid (5%), incubated at 37°C. Its phenotypic and genotypic descriptions are presented in this paper with a full annotation of its genome sequence. This genome consists of 3,104,261 bp in length and contains 3,074 predicted genes, including 3,012 protein-coding genes and 62 RNA-coding genes. Strain GD2 T significantly produces butyrate and is frequently found among available 16S rRNA gene amplicon datasets, which leads consideration of Intestinimonas massiliensis as an important human gut commensal., (© 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Bacterial adhesion is a key step to prevent environmental problems called acid mine drainage or to improve leaching efficiency in industry, since it initiates and enhances bioleaching. Thus, to analyze bacterial adhesion and to understand this process is crucial. In this study atomic force microscopy equipped with a pyrite or chalcopyrite tip was applied to study the adhesion of Sulfobacillus thermosulfidooxidans. The results illustrate that planktonic cells of both pyrite- and sulfur-grown cells of S. thermosulfidooxidans show more affinity to pyrite than to chalcopyrite (adhesion forces 2 nN versus 0.13 nN). However, the interactions between bacteria and chalcopyrite can be strengthened, if the bacteria are brought into contact with the chalcopyrite. The biofilm cells show low affinity to either pyrite or chalcopyrite. A high content of proteins in the extracellular polymeric substances collected from planktonic cells of S. thermosulfidooxidans and a low content of proteins collected from biofilm EPS indicates that proteins play an important role in initial adhesion. Analysis of adhesion force-distance curves reveal that adhesion by pyrite-grown cells is a complex interaction involving several bonding forces., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Clostridioides difficile is a spore-forming, anaerobic, intestinal pathogen that causes severe diarrhea that can lead to death. In 2011, C. difficile infected ∼500000 people in the USA and killed ∼29000 people. C. difficile infection (CDI) is the most common healthcare-related infection in the USA, leading to increased healthcare costs of $4.8 billion. This pathogen transmits via the oral-fecal route as a highly contagious and resilient spore. Upon exposure to primary bile acids in the intestine, C. difficile germinates, and in the absence of colonization resistance from the normal microbiota, the bacterium colonizes the colon and produces toxins. These toxins inhibit actin polymerization in host cells, leading to cell death. C. difficile cells can then sporulate in the intestine and exit the body via diarrheal shedding. In culture, sporulation is induced at stationary phase in a nutrient-limiting environment, but the intestinal triggers of sporulation are still unknown., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background and Aim: The study aims to elucidate the anti-inflammatory effect and mechanism of Roseburia intestinalis (R. intestinalis) in Crohn's disease (CD)., Methods: 16S-rRNA genome sequencing technique is used to detect the characteristics of intestinal microbiota in untreated CD patients and healthy controls. Then the study investigates the effects of R. intestinalis on disease activity index score, intestinal pathology, the differentiation of Treg cells, and the expressions of Thymic stromal lymphopoietin (TSLP), TGF-β and IL-10 by using TNBS colitis models. At the cellular level, the study uses LPS to stimulate Caco-2 cells to conduct inflammation models and then co-culture with R. intestinalis and detect changes of TSLP and TGF-β. The study then uses R. intestinalis to stimulate peripheral blood mononuclear cells, and the change of Treg cells was detected., Results: Genome sequencing of fecal samples from untreated CD patients (n = 10) revealed decreases in the abundance and diversity of intestinal microbiota, including R. intestinalis. Moreover, R. intestinalis reduced disease activity index scores, colon shortening, intestinal mucosal epithelial injury, and mucosal lymphocyte infiltration in a colitis mice model. It suppressed intestinal inflammation by increasing Treg cell numbers and expression of the anti-inflammatory cytokines TSLP, TGF-β, and interleukin-10 (P < 0.05). R. intestinalis also increased secretion of TSLP and TGF-β in lipopolysaccharide-treated Caco-2 cells., Conclusion: These findings suggest that R. intestinalis suppresses CD pathogenesis by inducing anti-inflammatory responses., (© 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Roseburia intestinalis (R. intestinalis) is one of the dominant intestinal bacterial microbiota and is decreased in patients with inflammatory bowel disease (IBD). It helps protect colonic mucosa against the development of inflammation and subsequent IBD, however its underlying mechanisms are unclear. The aim of the present study was to evaluate the anti‑inflammatory properties of R. intestinalis in vitro and in an animal model of IBD. The effects of R. intestinalis on disease activity index (DAI) scores, intestinal pathology, the expression of interleukin (IL)‑17 and the frequency of CD4+CD25+Foxp3+ regulatory T cells (Treg) were evaluated in vivo in a model of 2,4,6‑trinitrobenzenesulfonic acid solution (TNBS)‑induced colitis. Compared with the control group, TNBS‑treated mice had significantly higher secretion of IL‑17, higher DAI scores, a lower ratio of Treg, reduced colon lengths and higher histological scores for colon inflammation. The administration of R. intestinalis significantly downregulated the expression of IL‑17, increased the ratio of Treg and ameliorated the high DAI scores and the pathological signs of inflammation in the colon compared with mice treated with TNBS alone. Gene expression profiling was also used to detect the expression of IL‑17 in human IBD and healthy control specimens. To extend these findings to an in vitro model of inflammation the human colon epithelial cell line NCM460 was stimulated with lipopolysaccharide (LPS) to induce inflammation and co‑cultured with R. intestinalis and changes in IL‑17 expression were evaluated. R. intestinalis inhibited the LPS‑induced secretion of IL‑17 by NCM460 cells. In conclusion, these results demonstrate that R. intestinalis inhibits IL‑17 secretion and promotes Treg differentiation in colitis, suggesting that R. intestinalis could be of potential use in the treatment of IBD.

Butyricicoccus pullicaecorum and Megasphaera elsdenii inhabit the human intestine and have probiotic potential. The aim of this study was to evaluate the effects of B. pullicaecorum and M. elsdenii on the lifespan of Caenorhabditis elegans. They significantly (P < 0.05) extended the lifespan of C. elegans compared with Escherichia coli OP50, a standard food for the worm. Analysis of age-related biomarkers such as lipofuscin, body size, and locomotory activity showed that they retarded aging. They all failed to extend the lifespan of daf-12 or dbl-1 loss-of-function C. elegans mutants compared with E. coli OP50-fed worms. However, the increase in lifespan was observed in daf-16, jnk-1, pmk-1, and skn-1 mutants. Moreover, they increased the resistance of C. elegans to a human pathogen, Salmonella typhimurium. In conclusion, B. pullicaecorum and M. elsdenii extend the lifespan of C. elegans via the transforming growth factor-beta (TGF-β) pathway associated with anti-inflammatory processes in the innate immune system.