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PubMed2006

Effects of anti-Helicobacter pylori treatment and probiotic supplementation on intestinal microbiota.

The aims of this study were (i) to evaluate the effect of recommended antimicrobial treatment of Helicobacter pylori infection, consisting of clarithromycin, amoxicillin and lansoprazole, on intestinal microbiota and (ii) to determine the ability of a probiotic combination containing Lactobacillus rhamnosus GG, L. rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99 to prevent treatment-induced alterations in the intestinal microbiota. Faecal samples were obtained from 39 H. pylori-infected patients randomised into two treatment groups. In addition, 19 H. pylori-negative volunteers were included in the study as a control group. Samples were collected before, during and after treatment and microbiota were analysed by fluorescence in situ hybridisation and culture. The quantities of the predominant bacterial groups were altered significantly in both groups and disturbances were seen even 9 weeks after treatment was complete. Probiotics slightly counteracted the effects of anti-H. pylori treatment, seen as significantly less alterations in the total numbers of aerobes and lactobacilli/enterococci. At baseline, the composition of the microbiota between H. pylori-positive versus H. pylori-negative control individuals differed with regard to clostridia and the total number of anaerobes. The recommended treatment for H. pylori infection induces long-term disturbances in the intestinal microbiota. The probiotic combination appeared to result in only minor changes in the microbiota.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2006

Distinct signals from the microbiota promote different aspects of zebrafish gut differentiation.

All animals exist in intimate associations with microorganisms that play important roles in the hosts' normal development and tissue physiology. In vertebrates, the most populous and complex community of microbes resides in the digestive tract. Here, we describe the establishment of the gut microbiota and its role in digestive tract differentiation in the zebrafish model vertebrate, Danio rerio. We find that in the absence of the microbiota, the gut epithelium is arrested in aspects of its differentiation, as revealed by the lack of brush border intestinal alkaline phosphatase activity, the maintenance of immature patterns of glycan expression and a paucity of goblet and enteroendocrine cells. In addition, germ-free intestines fail to take up protein macromolecules in the distal intestine and exhibit faster motility. Reintroduction of a complex microbiota at later stages of development or mono-association of germ-free larvae with individual constituents of the microbiota reverses all of these germ-free phenotypes. Exposure of germ-free zebrafish to heat-killed preparations of the microbiota or bacterial lipopolysaccharide is sufficient to restore alkaline phosphatase activity but not mature patterns of Gal alpha1,3Gal containing glycans, indicating that the host perceives and responds to its associated microbiota by at least two distinct pathways.

Alkaline Phosphatase↗

PubMed2019

Dietary iron variably modulates assembly of the intestinal microbiota in colitis-resistant and colitis-susceptible mice.

Iron deficiency, a common comorbidity of gastrointestinal inflammatory disorders such as inflammatory bowel diseases (IBD), is often treated with oral iron supplementation. However, the safety of oral iron supplementation remains controversial because of its association with exacerbated disease activity in a subset of IBD patients. Because iron modulates bacterial growth and function, one possible mechanism by which iron may exacerbate inflammation in susceptible hosts is by modulating the intestinal microbiota. We, therefore, investigated the impact of dietary iron on the intestinal microbiota, utilizing the conventionalization of germ-free mice as a model of a microbial community in compositional flux to recapitulate the instability of the IBD-associated intestinal microbiota. Our findings demonstrate that altering intestinal iron availability during community assembly modulated the microbiota in non-inflamed wild type (WT) and colitis-susceptible interleukin-10-deficient (Il10-/-) mice. Depletion of luminal iron availability promoted luminal compositional changes associated with dysbiotic states irrespective of host genotype, including an expansion of Enterobacteriaceae such as Escherichia coli. Mechanistic in vitro growth competitions confirmed that high-affinity iron acquisition systems in E. coli enhance its abundance over other bacteria in iron-restricted conditions, thereby enabling pathobiont iron scavenging during dietary iron restriction. In contrast, distinct luminal community assembly was observed with dietary iron supplementation in WT versus Il10-/- mice, suggesting that the effects of increased iron on the microbiota differ with host inflammation status. Taken together, shifts in dietary iron intake during community assembly modulate the ecological structure of the intestinal microbiota and is dependent on host genotype and inflammation status.

Animals↗

PubMed2005

Biodiversity of the mucosa-associated microbiota is stable along the distal digestive tract in healthy individuals and patients with IBD.

BACKGROUND: The mucosa-associated microbiota, being very close to the inflammatory process associated with inflammatory bowel disease (IBD), may have a pathogenic role. We used a culture-independent method to analyze the mucosa-associated microbiota in IBD patients at various points of the distal digestive tract. METHODS: Thirty-five patients (20 with Crohn's disease, 11 with ulcerative colitis, and 4 controls) underwent colonoscopy. Biopsies (n = 126) were taken from 4 sites: the ileum, right colon, left colon, and rectum. Fecal samples were also obtained from 7 individuals. Temporal temperature gradient gel electrophoresis (TTGE) of 16S rDNA was used to evaluate dominant species diversity. TTGE profiles were compared using software that measures the degree of similarity. RESULTS: In a given individual, the overall similarity percentage between the 4 segments of the distal digestive tract was 94.7 +/- 4.0%, regardless of clinical status. The average similarity of all profiles for a given segment was 59.3 +/- 18.3% in the overall population. Dendrogram analysis showed that TTGE profiles did not cluster with clinical status. Differences were observed between the dominant fecal microbiota and the mucosa-associated microbiota of all 4 sites, with similarity percentages less than 92%. CONCLUSIONS: These results confirm that the dominant species differ between the mucosa-associated and fecal microbiota. They also show that, in a given individual, the microbiota is relatively stable along the distal digestive tract, showing a slight evolution in dominant species diversity from the ileum to the rectum, in both healthy subjects and patients with IBD.

Adolescent↗

PubMed2006

Human faecal microbiota develops the ability to degrade type 3 resistant starch during weaning.

BACKGROUND: Colonisation of the human colon starts immediately after birth. Bacterial composition is substantially influenced by the type of feeding. During weaning, microbiota diversifies considerably to finally approach the composition of that of adults. The aim of this study was to investigate the ability of colonic microbiota obtained from different age groups to ferment resistant starch (RS). METHODS: Faecal samples of breast-fed and formula-fed infants, infants at weaning, adults and elderly subjects were used as inocula. Fermentation experiments were performed by applying a standardised in vitro batch method. Fermentability was established by measuring both metabolite production and substrate degradation. An RS type 3 (RS-3) was used as substrate; its behaviour was compared with that of lactulose (positive control), whereas inoculum without substrate was used as negative control. RESULTS: Overall fermentation patterns clearly showed that the human microbiota of all age groups is able to degrade lactulose. In contrast, RS-3 was found resistant to the attack by microbiota of both breast-fed and formula-fed infants. Bacteria collected from infants at weaning were able to degrade RS-3 completely, but slower compared with adults. With increasing age, RS-3 fermentation was observed to be slightly retarded again. CONCLUSIONS: Human faecal microbiota of all age groups is able to ferment lactulose in vitro quickly and completely. The ability to degrade RS-3, however, is only established during weaning. Whether fermentation-related production of short-chain fatty acids from RS-3 and concurrent modifications of the microbiota can result in potential health benefits to the host at this stage of life needs to be elucidated.

Adult↗

PubMed2005

Molecular analysis of jejunal, ileal, caecal and recto-sigmoidal human colonic microbiota using 16S rRNA gene libraries and terminal restriction fragment length polymorphism.

Microbiota in gut contents of jejunum, ileum, caecum and recto-sigmoid colon obtained from three elderly individuals at autopsy were compared using 16S rRNA gene libraries and terminal restriction fragment length polymorphism (T-RFLP). Random clones of 16S rRNA gene sequences were isolated after PCR amplification with universal primer sets of total genomic DNA extracted from each sample of gut contents. An average of 90 randomly selected clones were partially sequenced (about 500 bp). T-RFLP analysis was performed using the 16S rRNA gene amplified from each sample. The lengths of the terminal restriction fragments were analysed after digestion with HhaI and MspI. The jejunal and ileal microbiota consisted of simple microbial communities of streptococci, lactobacilli, 'Gammaproteobacteria', the Enterococcus group and the Bacteroides group. Most of the species were facultative anaerobes or aerobes. The Clostridium coccoides group and the Clostridium leptum subgroup, which are the most predominant groups in human faeces, were not detected in samples from the upper gastrointestinal tract. The caecal microbiota was more complex than the jejunal and ileal microbiota. The C. coccoides group, the C. leptum subgroup and the Bacteroides group were detected in the caecum. The recto-sigmoidal colonic microbiota consisted of complex microbial communities, with numerous species that belonged to the C. coccoides group, the C. leptum subgroup, the Bacteroides group, 'Gammaproteobacteria', the Bifidobacterium group, streptococci and lactobacilli, and included more than 26 operational taxonomic units. The results showed marked individual differences in the composition of microbiota in each region.

Aged↗

PubMed1997

Comparison of the indigenous oral microbiota and immunoglobulin responses of athymic (nu/nu) and euthymic (nu/+) mice.

The role of the immune system in the homeostasis of indigenous oral bacterial populations is poorly understood. In this study, we compared the evolution of the indigenous oral microbiota of specific pathogen-free athymic nude (nu/nu) BALB/c mice with that of their corresponding phenotypically normal (nu/-) littermates. We also evaluated corresponding salivary and serum antibody activities (IgA and IgG) against the predominant indigenous oral bacteria. The bacterial species recovered from the two mouse strains were Lactobacillus murinus, Enterococcus faecalis, Streptococcus oralis and Staphylococcus epidermidis. From 27 days of age, nu/+ and nu/nu mice had significantly different proportions of oral bacterial populations. When the microbiota stabilized (at 40 days of age), the total cultivable microbiota of nu/+ mice was dominated by L. murinus (65-85%), while that of nu/nu mice was dominated by E. faecalis (40-60%). The precise factors that alter the oral resident microbiota in nu/nu mice are unknown. We found that total salivary IgA levels were significantly lower in nu/nu mice, but no association were observed between the level of salivary IgA antibody against indigenous bacteria and the proportion of these indigenous bacteria in the oral microbiota. The change in the microbiota of nude mice may have been caused by other factors such as defects in other immune functions or cold stress.

Animals↗

PubMed2006

Temperature gradient gel electrophoresis of fecal 16S rRNA reveals active Escherichia coli in the microbiota of patients with ulcerative colitis.

Previous studies of the endogenous microbiota in patients with ulcerative colitis (UC) have not taken bacterial activity into account, yet bacteria with high transcriptional activity might have a more important pathophysiological role than inactive bacteria. We therefore analyzed the biodiversity of active bacteria in the fecal microbiota of UC patients, in comparison with that of healthy subjects. Feces were collected from nine patients with active UC and from nine healthy controls. Total DNA and RNA were extracted, and 16S ribosomal DNA and RNA were amplified by PCR and reverse transcription-PCR, respectively. Amplification products were compared by means of temporal temperature gradient gel electrophoresis (TTGE). Bands of interest were excised, sequenced, and identified by comparison with the GenBank database (NCBI). The dominant-species diversity based on RNA-derived TTGE profiles was significantly lower for UC patients than for healthy controls (P = 0.01). The mean similarity index between the "present" and "active" microbiota was 74% +/- 18% for UC patients. Comparison of the individual "active" microbiota identified a band that was present for eight UC patients and only two controls (89% versus 22%; P = 0.008). The band was sequenced for 6 patients and always corresponded to Escherichia coli. The biodiversity of active bacteria in the dominant fecal microbiota of patients with UC is lower than that of healthy subjects. E. coli is more represented in the active microbiota of UC patients. The possible pathophysiological role of this difference remains to be determined.

Adult↗

PubMed2005

Development of intestinal microbiota in mice and its possible interaction with the evolution of luminal IgA in the intestine.

The development of the intestinal microbiota and the evolution of the fecal IgA in mice were analyzed from 18 to 40 days old by PCR temperature gradient gel electrophoresis (TGGE) and ELISA, respectively. There were two events for the diversification of the intestinal microbiota from suckling to maturity. The first change occurred between days 21 and 22 after birth, when the diversity of the intestinal microbiota showed a remarkable increase at this time. The second change occurred from days 27 to 30 after birth, and the increase in the diversity of the intestinal microbiota ceased. The amount of fecal IgA decreased from days 18 to 20, remained low until day 22, on day 23, it recovered and then continued to increase. This study suggests that there are possible interactions between the development of intestinal microbiota and the evolution of intestinal secretion of IgA in mice, the same as in rats, although the second change in mice intestinal microbiota occurred a few days later than in rats. The decline in maternal IgA supply as the suckling period proceeded presumably allowed the bacterial colonization. As a consequence of this increase in bacterial colonization, the secretion of the self-SIgA was accelerated in the pups.

Animals↗

PubMed2005

Intestinal microbiota of patients with bacterial infection of the respiratory tract treated with amoxicillin.

The intestinal tract harbors a huge diversity of metabolically-active aerobic and anaerobic bacteria that interact, forming a complex ecosystem. This microbiota has an important role in human metabolism, nutrition, immunity, and protection against colonization by pathogenic microorganisms. Several factors can influence the intestinal microbiota; these include age, diet, inflammatory and infectious processes, and the use of antimicrobials. We investigated the influence of bacterial infection of the respiratory tract and of amoxicillin therapy on the normal intestinal microbiota of patients. Bacterial infectious processes affecting the respiratory tract were found to influence the intestinal microbiota, significantly decreasing the number of colony-forming units (CFUs) of Bacteroides spp. and Lactobacillus spp. per gram of feces. The use of amoxicillin also influenced the intestinal microbiota, significantly decreasing the CFU of Bifidobacterium spp. and Lactobacillus spp./g of feces. Changes in the composition of the intestinal microbiota need to be observed, since a decrease in the normal microorganisms can pose a number of hazards for hosts, including decreased resistance to colonization. With proper follow-up, health-care teams can minimize such hazards by implementing suitable therapy- and diet-related measures, thus reducing the occurrence of detrimental effects on the gastrointestinal ecosystem.

Acute Disease↗

PubMed2005

Subgingival microbiota in peri-implant mucosa lesions and adjacent teeth in partially edentulous patients.

BACKGROUND: Osseointegrated dental implants have been shown to be a predictable approach to provide the adequate support for the replacement of missing teeth. It has been observed that implants showing signs of peri-implantitis contain subgingival microbiota similar to that around natural teeth with periodontal disease. This study identified the subgingival microbiota around implants with peri-implant lesions and natural teeth in partially edentulous patients. METHODS: Clinical and radiographic parameters were recorded and microbial samples taken from 16 implants with signs of pocketing, 12 neighboring and 11 non-neighboring teeth to the affected implants in 11 patients and 15 stable implants in eight patients (controls). Samples were cultured using techniques for Enterobacteriaceae spp and facultative/anaerobic periodontal pathogens. Statistical analysis included Friedman test to establish differences between the subgingival microbiota cultured from implants and teeth and two-tailed Mann Whitney test and chi square to find differences in two separate samples (P < or = 0.05). RESULTS: There were statistical differences between the subgingival microbiota in peri-implant lesions and stable implants for Gram-negative enteric rods (P <0.05). P. gingivalis (1.42%) was detected in peri-implant lesions but not in stable implants. A significant correlation between the subgingival microbiota from implants and neighboring teeth for Gram-negative enteric rods (P = 0.023) and implants and non-neighboring teeth for P. gingivalis (P = 0.042) was found. The frequency detection of Gram-negative enteric rods (75%) and P. intermedia/nigrescens (25%) was higher in peri-implant lesions (P <0.05). CONCLUSIONS: The subgingival microbiota in peri-implant lesions showed high levels of periodontopathic bacteria and superinfecting bacteria compared to healthy stable implants. The role of superinfecting bacteria in the pathogenesis of peri-implant lesions needs further investigation.

Dental Implants↗

PubMed2002

The development of gut immune responses and gut microbiota: effects of probiotics in prevention and treatment of allergic disease.

The infant's immature intestinal immune system develops as it comes into contact with dietary and microbial antigens in the gut. The evolving indigenous intestinal microbiota have a significant impact on the developing immune system and there is accumulating evidence indicating that an intimate interaction between gut microbiota and host defence mechanisms is mandatory for the development and maintenance of a balance between tolerance to innocuous antigens and capability of mounting an inflammatory response towards potential pathogens. Disturbances in the mucosal immune system are reflected in the composition of the gut microbiota and vice versa. Distinctive alterations in the composition of the gut microbiota appear to precede the manifestation of atopic disease, which suggests a role for the interaction between the intestinal immune system and specific strains of the microbiota in the pathogenesis of allergic disorders. The administration of probiotics, strains of bacteria from the healthy human gut microbiota, have been shown to stimulate antiinflammatory, tolerogenic immune responses, the lack of which has been implied in the development of atopic disorders. Thus probiotics may prove beneficial in the prevention and alleviation of allergic disease.

Food Hypersensitivity↗

PubMed2026

Causal Relationships Between Oral Microbiota and Inflammatory Skin Diseases.

INTRODUCTION AND AIMS: The oral microbiome has been increasingly linked to systemic inflammation and immune dysregulation, but whether specific oral bacteria causally contribute to inflammatory skin diseases remains unclear due to confounding and reverse causation. This study aimed to assess the causal effects of 43 oral microbiota taxa on the risk of five inflammatory skin diseases using a Mendelian randomization (MR) approach. METHODS: We performed a two-sample MR analysis using genetic instruments for oral microbiota derived from publicly available genome-wide association studies and outcome data from the FinnGen consortium. Causal effects of oral taxa on systemic lupus erythematosus, vitiligo, pemphigus, localized scleroderma, and dermatitis herpetiformis were estimated. The inverse-variance weighted method served as the primary analysis, complemented by sensitivity analyses to evaluate horizontal pleiotropy, heterogeneity, and reverse causality. RESULTS: MR analyses identified several putative causal associations between oral microbiota and inflammatory skin diseases. Genus Granulicatella and an unknown Streptococcus species (ASV0009) showed causal effects on systemic lupus erythematosus. Family Lachnospiraceae_[XIV] and an unknown Rothia species (ASV0016) were associated with vitiligo. Five oral microbiota taxa demonstrated causal associations with pemphigus. Actinomyces species micronuciformis was linked to localized scleroderma. Order Fusobacteriales and an unknown Neisseria species (ASV0004) were associated with dermatitis herpetiformis. No significant heterogeneity or horizontal pleiotropy was detected in sensitivity analyses. CONCLUSION: This MR study provides genetic evidence supporting a causal role of specific oral bacteria in the development of several inflammatory skin diseases, highlighting the oral microbiome as a potential contributor to cutaneous autoimmunity and inflammation. CLINICAL RELEVANCE: Our findings highlight the putative role of the oral microbiome as a plausible candidate for mechanistic and clinical investigations into the prevention or adjunctive management of selected inflammatory skin diseases. However, oral hygiene improvement, targeted antimicrobials, and other microbiota-directed interventions were not directly tested in this MR study and remain hypothetical strategies requiring validation in experimental and clinical studies.

Humans↗

PubMed2026

Efficacy of pharmacological and microbiota-based therapies in preclinical models of autism spectrum disorder: a systematic review.

BACKGROUND: Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental condition in which pharmacological and microbiota-targeted interventions are emerging as promising therapeutic avenues. Animal models are the main tool to investigate etiology, molecular mechanisms and screening for pharmacological therapies. Methodological differences, outcome measure variability, incomplete reporting, biological confounders, and overgeneralization of the results made evaluating innovative pharmacological agents challenging. These limitations in the field highlight a need for systematic and standardized research to reliably assess and translate pharmacological interventions from ASD animal models to human clinical relevance. SUBJECTS: This systematic review synthesized efficacy evidence for pharmacological and microbiota-based therapies across established ASD animal models. RESULTS: We identified 52 recent (2010-2025) studies that reported key ASD behavioral outcomes after pharmacological or microbiota-focused treatments. Interventions were grouped into therapeutic classes - including oxytocinergic agents, E/I balance therapeutic targets, metabolic drugs, cannabinoids, purine-based interventions and emerging targets - alongside microbiota-directed strategies such as probiotics, prebiotics, and fecal microbiota transplantation. By integrating effect directions and robustness across models, we identified most potential drug candidates, evaluated the efficacy of novel strategies, and recognized critical translational gaps. The reviewed studies demonstrate that ASD-like behavioral deficits in preclinical models can be modulated through interventions targeting diverse biological systems, including neurotransmission, neuroinflammation, metabolism, and the gut-brain axis. CONCLUSIONS: These findings support the multifactorial nature of ASD pathophysiology which arises from a network of interacting systemic processes rather than a single molecular defect. It could explain the limited success of traditionally narrowly targeted interventions and suggest a paradigm shift into a more systemic approach.

Animals↗

PubMed2026

Postpartum compositional changes in bovine calf nasal and dam vaginal microbiota and concurrent immune responses following prepartum betadine lavages.

As interest in bovine reproductive tract microbial communities increases, there remains limited information on how the insult of parturition influences postpartum dam reproductive microbiota and early-life microbial development. The objective of this study was to characterize postpartum changes in dam vaginal microbiota and neonatal calf nasal microbiota following transient prepartum disruption of the dam vaginal microbiota using betadine lavages (BLGs), and to evaluate concurrent systemic immune responses in dams and calves. Multiparous beef cows (n = 12) were randomly assigned to either BLG (n = 7) or control (CON; n = 5) 3 wk prior to the expected calving date, and dam vaginal swabs, calf nasal swabs, and blood were collected at 0 (+1), 15 (±1), 30 (±1), and 60 (±1) d postpartum. Samples from Angus cow-calf pairs (n = 12) underwent 16S rRNA gene sequencing with standard contamination controls and QIIME2 processing. Blood samples were analyzed using the D2Dx immunity assay to evaluate systemic humoral immune responses. Microbial alpha diversity (ANOVA), Bray-Curtis beta diversity (PERMANOVA), taxonomic composition (LEfSe), and D2Dx immune responses (repeated-measures mixed model) were analyzed (P < 0.05). In calves, treatment influenced nasal alpha diversity at d 0 (P = 0.03), while nasal beta diversity tended to differ at d 0 (P = 0.08); however, treatment effects were not detected at d 15, 30, or 60 for alpha diversity (P ≥ 0.76) or beta diversity (P ≥ 0.14). Calf nasal communities shifted over time (P = 0.001), with d 0 differing from d 15, 30, and 60, and beta diversity differing over time (P = 0.006). In dams, BLG did not alter vaginal alpha diversity (P ≥ 0.42) or beta diversity (P ≥ 0.14) over time, and time did not affect vaginal alpha diversity (P = 0.60) while vaginal beta diversity tended to shift over time (P = 0.06). Postpartum dam vaginal and calf nasal communities differed compositionally regardless of time (P < 0.05). Systemic immune responses, measured via D2Dx scores, fluctuated postpartum in dams (day effect: P < 0.001) and calves (day effect: P < 0.001), with BLG calves tending toward decreased immune response compared with CON (P = 0.08). Prepartum BLG minimally influenced neonatal nasal microbial diversity at birth and did not alter postpartum dam vaginal community structure, while calf nasal microbiota and D2Dx immune responses changed markedly over the first 60 d of life.

Animals↗

PubMed2026

Sex-Dependent Microbial and Host Profiles Following Fecal Microbiota and Bifidobacterium longum Treatment in Stress-Induced Gut Dysbiosis.

BACKGROUND/AIMS: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder influenced by stress, microbial dysbiosis, and immune activation. Microbiota-directed therapies, including fecal microbiota transplantation and probiotics, show promise, but their sex-specific effects remain unclear. We compared the therapeutic effects of lyophilized fecal microbiota (LFM) with Bifidobacterium longum BBH016 in male and female Wistar rats subjected to repeated water avoidance stress. METHODS: Fecal pellet output (FPO), colonic mast cell infiltration, and fecal short-chain fatty acids were measured. Gut microbial composition and function were analyzed by 16S rRNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway prediction. RESULTS: Both interventions significantly reduced FPO and mast cell infiltration in males but had less pronounced effects in females. Microbiota analyses revealed sex-dependent responses, with distinct microbial trajectories in each treatment group. Using linear discriminant analysis effect size, we identified seven key taxa with treatment- or sex-specific enrichment. Alistipes onderdonkii and Bacteroides uniformis consistently increased in both LFM- and B. longum-treated groups, regardless of sex. Bacteroides finegoldii and Barnesiella intestinihominis were specifically enriched in the LFM group. In males, Blautia faecis and Fusicatenibacter saccharivorans were enriched following the interventions, whereas Parabacteroides goldsteinii appeared exclusively in stressed males. Functional predictions revealed the enrichment of estrogen signaling and bile acid pathways in males and the attenuation of proinflammatory pathways in females following LFM. Correlations between microbial taxa and host outcomes were predominantly observed in male rats. CONCLUSIONS: These findings highlight sex-specific microbial and host responses to microbiota-targeted therapies in a stress-induced IBS model, emphasizing sex as a biological variable in designing personalized microbiome-based treatments.

Animals↗

PubMed2026

Multi-Omic Insights Into Mediterranean Diet-Associated Microbiota.

This study aimed to evaluate the gut microbiota and mycobiota composition, depending on the Mediterranean diet (MD) adherence, using metataxonomics. Combining metagenomics and metatranscriptomics, we also investigate the gene expression level in the bacterial community. Two groups of healthy subjects greatly differing in adherence were selected. Significant differences in microbiota composition were observed between individuals with high adherence (HAMD; mean 10.5 +/- 0.9 points) and low adherence (LAMD; 5.23 +/- 83 points). Notably, the olive oil, vegetable, and fruit consumption presented an important discriminant power between groups. Saccharomyces, Penicillium, and Candida were the most abundant genera. Mycobiota richness was higher in LAMD than in HAMD. Aspergillus was identified as a biomarker for LAMD, whereas Yarrowia, a potential probiotic, was a biomarker for HAMD. Metatranscriptomics indicated that Bacillota was the most metabolically active phylum in the gut microbiota. The low-abundant genus, Methanobrevibacter, showed high transcriptional activity, contributing to the crucial methanogenesis process. Gene expression analyses further highlighted functional differences. Overall, HAMD microbiota presented increased metabolic activity, protein synthesis, and cellular mobility. Overexpression of flagellin and urease genes may enhance immune response in HAMD. Further metatranscriptomic studies are necessary to deepen our understanding of intestinal microbiota transcriptional programs and their interactions with the diet and human health.

Humans↗

PubMed2024

Dissecting the anti-obesity components of ginseng: How ginseng polysaccharides and ginsenosides target gut microbiota to suppress high-fat diet-induced obesity.

INTRODUCTION: Ginseng demonstrates therapeutic potential in treating obesity, with both experimental and clinical studies suggesting its anti-obesity effects are mediated by gut microbiota. Nonetheless, the specific chemical components responsible for this effect remain largely unidentified. OBJECTIVES: This study aims to investigate the anti-obesity effects and mechanisms of ginseng polysaccharides (GP) and ginsenosides (GS), the primary chemical components of ginseng, with a focus on their impact on gut microbiota. METHODS: The impact of GP and GS on high-fat diet (HFD)-induced obesity was assessed using a mouse model. Molecular mechanisms were explored through a combination of chemical analysis, metagenomics, RT-qPCR, ELISA, and biochemical assays. RESULTS: GP or GS administration effectively prevented adiposity in HFD-fed mice, and both effects were mediated by gut microbiota. Chemical analysis revealed diverse glycosyl groups in GP and GS. Metagenomics data suggested that GP-enriched species, e.g., Bacteroides stercorirosoris and Clostridiales bacterium encoded carbohydrate-active enzymes GH35, GH43 and PL9_1, while GS-enriched Sulfurospirillum halorespirans encoded GH16_5. These enzymes facilitated the utilization of glycosyl groups in GP and GS, selectively stimulating bacterial growth and reshaping the gut microbiota. Furthermore, bacterial species enriched by GP or GS encoded specific functional genes involved in short-chain fatty acid (SCFA) synthesis (K00625 and K00925 for GP; K18118, K00100, and K18122 for GS) and intestinal gluconeogenesis (IGN) (K01678, K00024, and K01596 for GP; K18118 and K00278 for GS). Consequently, the SCFA-GLP-1/PYY signaling and IGN were activated by both GP and GS to ameliorate obesity phenotypes. CONCLUSION: GP and GS, containing diverse glycosyl groups, selectively stimulate specific gut bacteria, triggering mechanisms involved in SCFA-GLP-1/PYY signaling and IGN activation to reduce adiposity in HFD-fed mice. The study enhances understanding of the chemical components crucial for the gut microbiota-mediated anti-obesity effect of ginseng. The mechanistic understanding provides valuable insights for developing ginseng-based drugs or health products to combat obesity.

Gastrointestinal Microbiome↗