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Background: The evolving infant gut microbiome influences host immune development and later health outcomes. Early antibiotic exposure could impact microbiome development and contribute to poor outcomes. Here, we use a prospective longitudinal birth cohort of n = 323 healthy term African American children to determine the association between antibiotic exposure and the gut microbiome through shotgun metagenomics sequencing as well as bile acid profiles through liquid chromatography-mass spectrometry., Results: Stool samples were collected at ages 4, 12, and 24 months for antibiotic-exposed (n = 170) and unexposed (n = 153) participants. A short-term substudy (n = 39) collected stool samples at first exposure, and over 3 weeks following antibiotics initiation. Antibiotic exposure (predominantly amoxicillin) was associated with minimal microbiome differences, whereas all tested taxa were modified by breastfeeding. In the short-term substudy, we observed microbiome differences only in the first 2 weeks following antibiotics initiation, mainly a decrease in Bifidobacterium bifidum. The differences did not persist a month after antibiotic exposure. Four species were associated with infant age. Antibiotic exposure was not associated with an increase in antibiotic resistance gene abundance or with differences in microbiome-derived fecal bile acid composition., Conclusions: Short-term and long-term gut microbiome perturbations by antibiotic exposure were detectable but substantially smaller than those associated with breastfeeding and infant age., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the Institutional Review Board (IRB) at Children’s Hospital of Philadelphia (IRB 14–010833). Consent for publication: The IGram study enrolled pregnant African American mothers and their newborn infants. The purpose of the research study was to learn more about the bacteria normally living in the child’s gut, how it is transferred from mother to child, and whether it affects the child’s growth in the first 3 years of life. The IGRAM data used in this publication are consistent with the stated purpose of the research. The Institutional Review Board-approved consent documents included language that allowed participants to indicate whether they would like to have their information included in future research. Subjects may participate in the original research without their information (even if de-identified) being included in future research. Competing interests: Dr Elovitz receives salary support from NIAID, NICHD and NINR. She serves as a consultant with equity for Mirvie. No other disclosures were reported., (© 2025. The Author(s).)

Probiotics and synbiotics can mitigate the negative health consequences of early-life antibiotic exposure. This study aimed to determine whether supplementation with Bifidobacterium longum ssp. infantis 79 (B79) or synbiotics composed of B79 and 2'-fucosyllactose (2'-FL) could mitigate the negative impact of ceftriaxone exposure in early life. We found that antibiotic-treated mice exhibited lower BW, crypt depth, short-chain fatty acid content, and α-diversity indices at weaning, whereas they had increased relative abundance of opportunistic pathogens (such as Enterococcus and Staphylococcus) and decreased relative abundance of intestinal commensal bacteria. Supplementation with B79 and 2'-FL revived these antibiotic-induced negative effects and reduced the mRNA expression of IL-6, IL-12p40, and TNF-α in the spleen at weaning. Moreover, B79 and 2'-FL supplementation persistently improved crypt depth, propionic acid synthesis, and IgG and secretory IgA production, as well as revived the gut microbiota structure and composition in adulthood. Overall, our study suggests that early-life supplementation with B79 alone or in combination with 2'-FL can mitigate ceftriaxone-induced negative effects on the gut microbiota and intestinal and immune development of mice, and these improvements can partially last into adulthood., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Background: The human gut microbiota develops in concordance with its host over a lifetime, resulting in age-related shifts in community structure and metabolic function. Little is known about whether these changes impact the community's response to microbiome-targeted therapeutics. Providing critical information on this subject, faecal microbiomes of subjects from six age groups, spanning from infancy to 70-year-old adults (n = six per age group) were harvested. The responses of these divergent communities to treatment with the human milk oligosaccharide 2'-fucosyllactose (2'FL), fructo-oligosaccharides (FOS), and lactose was investigated using the Ex vivo SIFR ® technology that employs bioreactor fermentation and is validated to be predictive of clinical findings. Additionally, it was evaluated whether combining faecal microbiomes of a given age group into a single pooled microbiome produced similar results as the individual microbiomes., Results: First, marked age-dependent changes in community structure were identified. Bifidobacterium levels strongly declined as age increased, and Bifidobacterium species composition was age-dependent: B. longum , B. catenulatum/pseudocatenulatum, and B. adolescentis were most prevalent for breastfed infants, toddlers/children, and adults, respectively. Metabolomic analyses (LA-REIMS) demonstrated that these age-dependent differences particularly impacted treatment effects of 2'FL (more than FOS/lactose). Further analysis revealed that while 2'FL enhanced production of short-chain fatty acids (SCFAs) and exerted potent bifidogenic effects, regardless of age, the specific Bifidobacterium species enhanced by 2'FL, as well as subsequent cross-feeding interactions, were highly age-dependent. Furthermore, single-pooled microbiomes produced results that were indicative of the average treatment response for each age group. Nevertheless, pooled microbiomes had an artificially high diversity, thus overestimating treatment responses (especially for infants), did not recapitulate interindividual variation, and disallowed for the correlative analysis required to unravel mechanistic actions., Conclusions: Age is an important factor in shaping the gut microbiome, with the dominant taxa and their metabolites changing over a lifetime. This divergence affects the response of the microbiota to therapeutics, demonstrated in this study using 2'FL. These results evidence the importance of screening across multiple age groups separately to provide granularity of how therapeutics impact the microbiome and, consequently, human health.

To explore the mechanism by which vinegar-processed Euphorbiae Pekinensis Radix regulates gut microbiota and reduces intestinal toxicity, this study aimed to identify key microbial communities related to vinegar-induced detoxification and verify their functions. Using a derivatization method, the study measured the content of short-chain fatty acids(SCFAs) in feces before and after vinegar-processing of Euphorbiae Pekinensis Radix. Combined with the results of previous gut microbiota sequencing, correlation analysis was used to identify key microbial communities related to SCFAs content. Through single-bacterium transplantation experiments, the role of key microbial communities in regulating SCFAs metabolism and alleviating the intestinal toxicity of Euphorbiae Pekinensis Radix was clarified. Fecal extracts were then added to a co-culture system of Caco-2 and RAW264.7 cells, and toxicity differences were evaluated using intestinal tight junction proteins and inflammatory factors as indicators. Additionally, the application of a SCFAs receptor blocker helped confirm the role of SCFAs in reducing intestinal toxicity during vinegar-processing of Euphorbiae Pekinensis Radix. The results of this study indicated that vinegar-processing of Euphorbiae Pekinensis Radix improved the decline in SCFAs content caused by the raw material. Correlation analysis revealed that Bifidobacterium was positively correlated with the levels of acetic acid, propionic acid, isobutyric acid, n-butyric acid, isovaleric acid, and n-valeric acid. RESULTS:: from single-bacterium transplantation experiments demonstrated that Bifidobacterium could mitigate the reduction in SCFAs content induced by raw Euphorbiae Pekinensis Radix, enhance the expression of tight junction proteins, and reduce intestinal inflammation. Similarly, cell experiment results confirmed that fecal extracts from Bifidobacterium-transplanted mice alleviated inflammation and increased the expression of tight junction proteins in intestinal epithelial cells. The use of the free fatty acid receptor-2 inhibitor GLPG0974 verified that this improvement effect was related to the SCFAs pathway. This study demonstrates that Bifidobacterium is the key microbial community responsible for reducing intestinal toxicity in vinegar-processed Euphorbiae Pekinensis Radix. Vinegar-processing increases the abundance of Bifidobacterium, elevates the intestinal SCFAs content, inhibits intestinal inflammation, and enhances the expression of tight junction proteins, thereby improving the intestinal toxicity of Euphorbiae Pekinensis Radix.

Objective: This study aimed to evaluate the safety and probiotic properties of Bifidobacterium longum subsp. longum BL21 isolated from infant feces for use as a commercial probiotic strain., Methods: Whole-genome sequencing; physiological and biochemical assessments; enzymatic assays; metabolite, antibiotic sensitivity, cell adhesion and cytotoxicity, and tolerance tests; and a 14-day oral toxicity study were conducted., Results: BL21 exhibited genetic integrity, and its genome lacked genes related to antibiotic resistance or virulence. It was found to be non-pathogenic, had efficient carbohydrate metabolism and mucin degradation ability, and was free from biogenic amines. It also showed susceptibility to antibiotics, strong cell adhesion, and resilience to adverse conditions. The aforementioned results confirm that BL21 is a functional probiotic strain with genetic stability, enzymatic capabilities, and non-pathogenic properties that mean it is safe for oral consumption, demonstrating that it is a promising candidate for probiotic applications., Conclusion: The study demonstrates that BL21 is a genetically stable, non-pathogenic probiotic strain with metabolic potential. The strain lacks virulence and antibiotic resistance genes, and its resilience to gastrointestinal conditions, as well as the results of the 14-day oral toxicity study, suggest that BL21 is safe for oral consumption. However, further long-term studies and clinical trials are needed to confirm its safety and efficacy for therapeutic use., Competing Interests: Declaration of competing interest The authors of the manuscript titled " Extensive Genomic Characterization, Pre-Clinical Probiotic Evaluation, andSafety Analysisof Bifidobacterium longum subsp. longum BL21 Isolated from Infant Feces” declare the following potential conflicts of interest: Yao Dong, Yinan Zhang, Fei Xu, and Kang Zou declare no conflicts of interest related to this research. The authors affirm that there are no financial, personal, or professional relationships that could potentially bias or influence the interpretation of the findings presented in this manuscript., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study aimed to investigate the effect of ultrasound-assisted H 2 O 2 (US/H 2 O 2 ) reaction on degradation parameters and kinetics, physicochemical properties and prebiotic activity of longan polysaccharide (LP). Results showed that US/H 2 O 2 had a synergistic effect on the degradation of LP, and its kinetic equation followed to the fist - order model. US/H 2 O 2 degradation did not change the chemical and monosaccharide composition of LP but altered their ratio. Compared with LP, three degraded polysaccharides (DLPs) displayed lower molecular weight, particle size and viscosity, but higher solubility. SEM and AFM revealed that US/H 2 O 2 degradation led to significant differences in the microstructure and solution conformation of LP. Moreover, LP and DLPs showed different proliferation effects on four lactobacilli and bifidobacteria strains, among which DLP-8 (degraded for 8 h) exhibited the strongest prebiotic activity. US/H 2 O 2 could be effectively applied to the degradation of LP to improve its physicochemical properties and bioactivities., 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 © 2024 Elsevier B.V. All rights reserved.)

Microbial exopolysaccharides (EPSs) have attracted extensive attention for their biological functions in antioxidant activities. In this study, we characterized a novel EPS produced by Bifidobacterium pseudocatenulatum Bi-OTA128 which exhibited the highest antioxidant capacity compared to nine other ropy bacterial strains, achieving 76.50 % and 93.84 % in DPPH· and ABTS· + scavenging activity, and ferric reducing power of 134.34 μM Fe 2+ . Complete genomic analysis identified an eps gene cluster involved in the EPS biosynthesis of Bi-OTA128 strain, which might be responsible for its ropy phenotype. The EPS was then isolated and purified by a DEAE-Sepharose Fast Flow column. A single elution part EPS 128 was obtained with a recovery rate of 43.5 ± 1.78 % and a total carbohydrate content of 93.6 ± 0.76 %. Structural characterization showed that EPS 128 comprised glucose, galactose, and rhamnose (molar ratio 4.0:1.2:1.1), featuring a putative complex backbone structure with four branched chains and an unusual acetyl group at O-2 of terminal rhamnose. Antioxidant assay in vitro indicated that EPS 128 exhibited antioxidant potential with 50.52 % DPPH· and 65.40 % ABTS· + scavenging activities, reaching 54.3 % and 70.44 % of the efficacy of standard Vitamin C at 2.0 mg/L. Furthermore, EPS 128 showed protective effects against H 2 O 2 -induced oxidative stress in HepG2 cells by reducing cellular reactive oxygen species (ROS) and increasing cell viability. These findings present the first comprehensive report of an antioxidant EPS from B. pseudocatenulatum, highlighting its potential as a natural antioxidant for applications in the food industry and clinical settings., 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 © 2024 Elsevier GmbH. All rights reserved.)

Carvacrol and thymol (CAT) have been widely recognized for their antimicrobial and anti-inflammatory properties, yet their specific effects on colitis and the mechanisms involved remain insufficiently understood. This study establishes a causative link between CAT administration and colitis mitigation, primarily through the enhancement of Bifidobacterium pseudolongum abundance in the colon. This increase promotes the production of secondary bile acids, particularly hyodeoxycholic acid (HDCA) and 12-ketodeoxycholic acid (12-KCAC), which exert anti-inflammatory effects. Notably, CAT does not alleviate colitis symptoms in germ-free mice, indicating the necessity of gut microbiota. This research uncovers a novel regulatory mechanism where HDCA and 12-KCAC inhibit colonic inflammation by reducing the expression of transmembrane guanylate cyclase 1A in the colonic epithelium. This downregulation elevates intracellular Ca 2+ and cGMP levels, activating protein kinase G (PKG). Activated PKG subsequently suppresses the mTOR signaling pathway, thereby ameliorating dextran sulfate sodium (DSS)-induced colonic damage. These findings highlight potential metabolites and therapeutic targets for preventing and treating colitis. Bifidobacterium pseudolongum, HDCA, and 12-KCAC emerge as promising candidates for therapeutic interventions in colitis and related disorders characterized by impaired tight junction function., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Recent studies have linked Ruminococcus gnavus to inflammatory bowel disease and Fusobacterium nucleatum to various cancers. Agarooligosaccharides (AOS), derived from the acid hydrolysis of agar, have shown significant inhibitory effects on the growth of R. gnavus and F. nucleatum at concentrations of 0.1 and 0.2%, respectively. RNA sequencing and quantitative reverse-transcription PCR analyses revealed the downregulation of fatty acid biosynthesis genes ( fab genes) in these bacteria when exposed to 0.1% AOS. Furthermore, AOS treatment altered the fatty acid composition of R. gnavus cell membranes, increasing medium-chain saturated fatty acids (C8, C10) and C18 fatty acids while reducing long-chain fatty acids (C14, C16). In contrast, no significant growth inhibition was observed in several strains of Bifidobacteria and Lactobacillales at AOS concentrations of 0.2 and 2%, respectively. Co-culture experiments with R. gnavus and Bifidobacterium longum in 0.2% AOS resulted in B. longum dominating the population, constituting over 96% post-incubation. In vivo studies using mice demonstrated a significant reduction in the Lachnospiraceae family, to which R. gnavus belongs, following AOS administration. Quantitative PCR also showed lower levels of the nan gene, potentially associated with immune disorders, in the AOS group. These findings suggest that AOS may introduce a novel concept in prebiotics by selectively inhibiting potentially pathogenic bacteria while preserving beneficial bacteria such as Bifidobacteria and Lactobacillales.

This study investigated the physicochemical properties, digestive stability, and in vitro fermentation behavior of Polygonatum kingianum polysaccharide (PKP) fractions (PKP60, PKP70, PKP80) obtained through graded ethanol precipitation. High-performance gel permeation chromatography revealed significant molecular weight differences among the fractions, while reverse-phase high-performance liquid chromatography indicated consistent monosaccharide types with variations in their proportions. Uronic acid analysis confirmed that all polysaccharide fractions met the criteria for neutral polysaccharides. Congo red staining confirmed the presence of a triple-helix structure in all PKP fractions. Comprehensive analysis demonstrated that these fractions remained stable during in vitro digestion, as evidenced by consistent molecular weights and total carbohydrate content, with no significant production of free monosaccharides or reducing sugars. All PKP fractions were fermented by gut microbiota, resulting in the production of short-chain fatty acids. Beta diversity and structural analyses of gut microbiota revealed distinct modulatory effects associated with each PKP fraction. The PKP fractions promoted probiotic growth, especially PKP70, which significantly enhanced Bifidobacterium proliferation, indicating strong prebiotic potential. These findings underscore the importance of isolation and purification methods in determining the functionality and gut microbiota-modulating effects of plant-derived polysaccharides, emphasizing the need for in-depth research that extends beyond merely evaluating their source., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Kratom (Mitragyna speciosa) has a long history of traditional use. It contains various alkaloids and polyphenols. The properties of kratom's alkaloids have been well-documented. However, the property of kratom's polyphenols in water-soluble phase have been less frequently reported. This study assessed the effects of water-soluble Mitragyna speciosa (kratom) extract (MSE) on gut microbiota and their metabolite production in fecal batch culture., Results: The water-soluble kratom extract (MSE0) and the water-soluble kratom extract after partial sugar removal (MSE50) both contained polyphenols, with total phenolic levels of 2037.91 ± 51.13 and 3997.95 ± 27.90 mg GAE/g extract, respectively and total flavonoids of 81.10 ± 1.00 and 84.60 ± 1.43 mg CEQ/g extract. The gut microbiota in fecal batch culture was identified by 16S rRNA gene sequencing at 0 and 24 h of fermentation. After fermentation, MSE50 stimulated the growth of Bifidobacterium more than MSE0. MSE0 gave the highest total fatty acids level among the treatments. The phenolic metabolites produced by some intestinal microbiota during fecal fermentation at 24 h were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The major metabolite of biotransformation of both water-soluble MSEs by intestinal microbiota was pyrocatechol (9.85-11.53%)., Conclusion: The water-soluble MSEs and their produced metabolites could potentially be used as ingredients for functional and medicinal food production that supports specific gut microbiota. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Bifidobacteria are commonly used as probiotics in the food industry. The resistance of Bifidobacterium species to antibiotics is closely linked to food safety. However, we still lack a system for the safety evaluation of antibiotic resistance in bifidobacteria, and genus-level microbiological cut-off values remain in use for the determination of phenotypic resistance of Bifidobacterium strains to a given antibiotic. Here, we collected a total of 422 gut-derived bifidobacterial strains isolated from Chinese population and identified their phenotypic resistance profiles against ampicillin, amoxicillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, rifampicin, tetracycline, trimethoprim, and vancomycin. Different Bifidobacterium species were found to have varying tolerances to the same antibiotic; therefore, we further established species-specific cut-off values for bifidobacterial species to ten antibiotics. Species-specific rather than genus-specific cut-off values for species belonging to the same taxon were considered more suitable to determine the phenotypic resistance of a Bifidobacterium strain. Moreover, a comprehensive scanning of antibiotic resistance genes in all Bifidobacterium strains tested revealed that the existence of the tetracycline resistance gene tet(W) and the erythromycin/clindamycin resistance gene ErmX is closely related to host phenotypes. Our findings provide guidance and reference values at both phenotype and genotype levels for the safe application of bifidobacteria in the food industry and the development of probiotic resistance evaluation standards., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Mangosteen (Garcinia mangostana L.) is a tasty, polyphenol-rich tropical fruit. The edible part is highly appreciated by its aroma, taste and texture. The non-edible part, rich in polyphenols, has been traditionally used in Thai medicine. In this work, flavonoids and phenolic acid/derivatives were identified in mangosteen extracts (ME) from edible and non-edible portions. We first studied the effects of MEs on the growth, metabolism, antioxidant capacity, biofilm formation and antimicrobial capacity of eight bifidobacteria and lactobacilli strains from intestinal origin and two commercial probiotic strains (BB536 and GG). ME concentrations higher than 10-20 % were inhibitory for all strains. However, ME concentrations of 5 % significantly (P < 0.01) increased all strains antioxidant capacity, reduced biofilm-formation, and enhanced inhibition against Gram-positive pathogens. To apply these knowledge, bifunctional fermented milk products were elaborated with 5 % ME and individual strains, which were selected taking into account their growth with ME, and the widest range of values on antioxidant capacity, biofilm formation and antimicrobial activity (bifidobacteria INIA P2 and INIA P467, lactobacilli INIA P459 and INIA P708, and reference strain GG). Most strains survived well manufacture, refrigerated storage and an in vitro simulation of major conditions encountered in the gastrointestinal tract. As expected, products supplemented with ME showed higher polyphenol content and antioxidant capacity levels than control. After sensory evaluation, products containing strains INIA P2, INIA P708 and GG outstood as best., 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 © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Our understanding of particular gut microbiota members such as Bifidobacterium and Enterococcus in low-middle-income countries remains very limited, particularly early life strain-level beneficial traits. This study addresses this gap by exploring a collection of bacterial strains isolated from the gut of Zimbabwean infants; comparing their genomic characteristics with strains isolated from infants across North America, Europe, and other regions of Africa., Materials and Method: From 110 infant stool samples collected in Harare, Zimbabwe, 20 randomly selected samples were used to isolate dominant early-life gut microbiota members Bifidobacterium and Enterococcus. Isolated strains were subjected to whole genome sequencing and bioinformatics analysis including functional annotation of carbohydrates, human milk oligosaccharide (HMO) and protein degradation genes and clusters, and the presence of antibiotic resistance genes (ARGs)., Results: The study observed some location-based clustering within the main five identified taxonomic groups. Furthermore, there were varying and overall species-specific numbers of genes belonging to different GH families encoded within the analysed dataset. Additionally, distinct strain- and species-specific variances were identified in the potential of Bifidobacterium for metabolizing HMOs. Analysis of putative protease activity indicated a consistent presence of gamma-glutamyl hydrolases in Bifidobacterium, while Enterococcus genomes exhibited a high abundance of aspartyl peptidases. Both genera harboured resistance genes against multiple classes of antimicrobial drugs, with Enterococcus genomes containing a higher number of ARGs compared to Bifidobacterium, on average., Conclusion: This study identified promising probiotic strains within Zimbabwean isolates, offering the potential for early-life diet and microbial therapies. However, the presence of antibiotic resistance genes in infant-associated microbes raises concerns for infection risk and next-stage probiotic development. Further investigation in larger cohorts, particularly in regions with limited existing data on antibiotic and probiotic use, is crucial to validate these initial insights., Impact Statement: This research represents the first investigation of its kind in the Zimbabwean context, focusing on potential probiotic strains within the early-life gut microbiota. By identifying local probiotic strains, this research can contribute to the development of probiotic interventions that are tailored to the Zimbabwean population, which can help address local health challenges and promote better health outcomes for infants. Another essential aspect of the study is the investigation of antimicrobial resistance genes present in Zimbabwean bacterial strains. Antimicrobial resistance is a significant global health concern, and understanding the prevalence and distribution of resistance genes in different regions can help inform public health policies and interventions., (© 2024. The Author(s).)

Trehalose (α-d-glucopyranosyl-(1-1)-α-D-glucopyranoside) has found applications in diverse food products as a sweetener, stabilizer, and humectant. Recent attention has focused on trehalose due to its contradictory effects on the virulence of Clostridium difficile. In this study, we investigate the impact of novel trehalose-derived galactooligosaccharides (Treh-GOS) on the human gut microbiota using in vitro fecal fermentation models. Distinct Treh-GOS structures elicit varying taxonomic responses. For instance, β-Gal-(1-4)-trehalose [DP3(1-4)] leads to an increase of Bifidobacterium, comparable to results observed with commercial GOS. Conversely, β-Gal-(1-6)-trehalose [DP3(1-6)] prompts an increase in Lactobacillus. Notably, both of these trisaccharides yield the highest concentrations of butyric acid across all samples. On the other hand, Treh-GOS tetrasaccharide mixture (DP4), featuring a novel trehalose galactosylation in both glucose units, fosters the growth of Parabacteroides. Our findings underscore the capacity of novel Treh-GOS to modulate the human gut microbiota. Consequently, these innovative galactooligosaccharides emerge as promising candidates for novel prebiotic applications., 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 results reported in this article., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

We studied the effect of enteral administration of the glucocorticoid deflazacort (DFC, 1.2 mg/kg per day, 28 days) on the state of skeletal muscles and tissue ultrastructure, as well as the composition of the colon microbiota in dystrophin-deficient mdx mice. DFC has been shown to reduce the intensity of degeneration/regeneration cycles in muscle fibers of mdx mice. This effect of DFC was accompanied by normalization of the size of sarcomeres of skeletal muscles of mdx mice, improvement of the ultrastructure of the subsarcolemmal population of mitochondria, and an increase in the number of organelles, as well as normalization of the number of contact interactions between the sarcoplasmic reticulum and mitochondria. In addition, DFC had a corrective effect on the colon microbiota of mdx mice, which manifested in an increase in the number of the Bifidobacterium genus microorganisms and a decrease in the level of E. coli with reduced enzymatic activity., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

(1) Background: Recently, academic studies are demonstrating that the cholesterol-lowering effects of pectin oligosaccharides (POSs) are correlated to intestinal flora. However, the mechanisms of POS on cholesterol metabolisms are limited, and the observations of intestinal flora are lacking integrative analyses. (2) Aim and methods: To reveal the regulatory mechanisms of POS on cholesterol metabolism via an integrative analysis of the gut microbiota, the changes in gut microbiota structure and metabolite composition after POS addition were investigated using Illumina MiSeq sequencing and non-targeted metabolomics through in vitro gut microbiota fermentation. (3) Results: The composition of fecal gut flora was adjusted positively by POS. POS increased the abundances of the cholesterol-related bacterial groups Bacteroidetes , Bifidobacterium and Lactobacillus , while it decreased conditional pathogenic Escherichia coli and Enterococcus , showing good prebiotic activities. POS changed the composition of gut microbiota fermentation metabolites (P24), causing significant changes in 221 species of fermentation metabolites in a non-targeted metabolomics analysis and promoting the production of short-chain fatty acids. The abundances of four types of cholesterol metabolism-related metabolites (adenosine monophosphate, cyclic adenosine monophosphate, guanosine and butyrate) were significantly higher in the P24 group than those in the control group without POS addition. (4) Conclusion: The abovementioned results may explain the hypocholesterolemic effects of POS and promotion effects on cholesterol efflux of P24. These findings indicated that the potential regulatory mechanisms of citrus POS on cholesterol metabolism are modulated by cholesterol-related gut microbiota and specific metabolites.

This study investigated the effect of astragalus polysaccharide (APS, an ingredient with hypoglycemic function in a traditional Chinese herbal medicine) on gut microbiota and metabolites of type 2 diabetes mellitus (T2DM) patients using a simulated fermentation model in vitro. The main components of APS were isolated, purified, and structure characterized. APS fermentation was found to increase the abundance of Lactobacillus and Bifidobacterium and decrease the Escherichia-Shigella level in the fecal microbiota of T2DM patients. Apart from increasing propionic acid, APS also caused an increase in all-trans-retinoic acid and thiamine (both have antioxidant properties), with their enrichment in the KEGG pathway associated with thiamine metabolism, etc. Notably, APS could also enhance fecal antioxidant properties. Correlation analysis confirmed a significant positive correlation of Lactobacillus with thiamine and DPPH-clearance rate, suggesting the antioxidant activity of APS was related to its ability to enrich some specific bacteria and upregulate their metabolites.

Pectin and its derivatives have been shown to modulate immune signaling as well as gut microbiota in preclinical studies, which may constitute the mechanisms by which supplementation of specific pectic polysaccharides confers protection against viral respiratory infections. In a double-blind, placebo-controlled rhinovirus (RV16) challenge study, healthy volunteers were randomized to consume placebo (0.0 g/day) (N = 46), low-dose (0.3 g/day) (N = 49) or high-dose (1.5 g/day) (N = 51) of carrot derived rhamnogalacturonan-I (cRG-I) for eight weeks and they were subsequently challenged with RV-16. Here, the effect of 8-week cRG-I supplementation on the gut microbiota was studied. While the overall gut microbiota composition in the population was generally unaltered by this very low dose of fibre, the relative abundance of Bifidobacterium spp. (mainly B. adolescentis and B. longum) was significantly increased by both doses of cRG-1. Moreover, daily supplementation of cRG-I led to a dose-dependent reduction in inter- and intra-individual microbiota heterogeneity, suggesting a stabilizing effect on the gut microbiota. The severity of respiratory symptoms did not directly correlate with the cRG-I-induced microbial changes, but several dominant groups of the Ruminococcaceae family and microbiota richness were positively associated with a reduced and hence desired post-infection response. Thus, the present results on the modulation of the gut microbiota composition support the previously demonstrated immunomodulatory and protective effect of cRG-I during a common cold infection., Competing Interests: Declaration of Competing Interest A.M. and R.A. are employees of NutriLeads. R.A. is the founder and CSO of NutriLeads and owns shares. A.M. is co-founder of NutriLeads and Senior R&D Director, owning shares. The study was funded by NutriLeads. NutriLeads provided the cRG-I study product. N.S. is an employee of Clinical Microbiomics, C.J., A.S. and W.d.V have no competing interests. All authors have approved the final manuscript and declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Resistance to antibiotics in newborns is a huge concern as their immune system is still developing, and infections and resistance acquisition in early life have short- and long-term consequences for their health. Bifidobacterium species are important commensals capable of dominating the infant gut microbiome and are known to be less prone to possess antimicrobial resistance genes than other taxa that may colonize infants. We aimed to study the association between Bifidobacterium -dominated infant gut microbiota and the antibiotic resistant gene load in neonates, and to ascertain the perinatal factors that may contribute to the antibiotic resistance acquisition. Two hundred infant fecal samples at 7 days and 1 month of age from the MAMI birth cohort were included in the study and for whom maternal-neonatal clinical records were available. Microbiota profiling was carried out by 16S rRNA amplicon sequencing, and targeted antibiotic resistance genes (ARGs) including tetM, tetW, tetO, blaTEM, blaSHV and ermB were quantified by qPCR. Infant microbiota clustered into two distinct groups according to their Bifidobacterium genus abundance: high and low. The main separation of groups or clusters at each time point was performed with an unsupervised non-linear algorithm of k-means partitioning to cluster data by time points based on Bifidobacterium genus relative abundance. Microbiota composition differed significantly between both groups, and specific bifidobacterial species were enriched in each cluster. Lower abundance of Bifidobacterium in the infant gut was associated with a higher load of antibiotic resistance genes. Our results highlight the relevance of Bifidobacterium genus in the early acquisition and establishment of antibiotic resistance in the gut. Further studies are needed to develop strategies to promote a healthy early colonization and fight against the spread of antibiotic resistances.

Bacteriocins are broad or narrow-spectrum antimicrobial compounds that have received significant scientific attention due to their potential to treat infections caused by antibiotic-resistant pathogenic bacteria. The genome of Bifidobacterium pseudocatenulatum MM0196, an antimicrobial-producing, fecal isolate from a healthy pregnant woman, was shown to contain a gene cluster predicted to encode Pseudocin 196, a novel lantibiotic, in addition to proteins involved in its processing, transport and immunity. Following antimicrobial assessment against various indicator strains, protease-sensitive Pseudocin 196 was purified to homogeneity from cell-free supernatant. MALDI TOF mass spectrometry confirmed that the purified antimicrobial compound corresponds to a molecular mass of 2679 Da, which is consistent with that deduced from its genetic origin. Pseudocin 196 is classified as a lantibiotic based on its similarity to lacticin 481, a lanthionine ring-containing lantibiotic produced by Lactococcus lactis . Pseudocin 196, the first reported bacteriocin produced by a B. pseudocatenulatum species of human origin, was shown to inhibit clinically relevant pathogens, such as Clostridium spp. and Streptococcus spp. thereby highlighting the potential application of this strain as a probiotic to treat and prevent bacterial infections.

Recently there is much debate in the scientific community over the impact of the food matrix on prebiotic efficacy of inulin-type fructans. Previous studies suggest that prebiotic selectivity of inulin-type fructans towards bifidobacteria is unaffected by the food matrix. Due to differences in study design, definitive conclusions cannot be drawn from these findings with any degree of certainty. In this randomised trial, we aimed to determine the effects that different food matrices had on the prebiotic efficacy of inulin-type fructans following a standardised 10-day, 4-arm, parallel, randomised protocol with inulin either in pure form or incorporated into shortbread biscuits, milk chocolate or a rice drink. Similar increases in Bifidobacterium counts were documented across all four interventions using both fluorescence in situ hybridisation (pure inulin: +0.63; shortbread: +0.59; milk chocolate: +0.65 and rice drink: +0.71 (log10 cells/g wet faeces) and 16S rRNA sequencing quantitative microbiome profiling data (pure inulin: +1.21 × 109; shortbread: +1.47 × 109; milk chocolate: +8.59 × 108 and rice drink: +1.04 × 109 (cells/g wet faeces) (all P ≤ 0.05). From these results, we can confirm that irrespective of the food matrix, the selectivity of inulin-type fructans towards Bifidobacterium is unaffected, yet the compositional make-up of the food matrix may have implications regarding wider changes in the microbiota.