Project description:A dysbiosis in the intestinal microbiome plays a role in the pathogenesis of several immunological diseases. These diseases often show a gender bias, suggesting gender differences in immune responses and in the intestinal microbiome. We hypothesized that gender differences in immune responses are associated with gender differences in microbiota. We demonstrated mouse strain dependent gender differences in the intestinal microbiome. Interestingly, a cluster of colonic genes (related to humoral and cell-mediated immune responses) correlated oppositely with microbiota species abundant in B6 females and in BALB/c males. This suggests that with different genetic backgrounds, gender associated immune responses are differentially regulated by microbiota. The net result was the same, since both mouse strains showed similar gender induced differences in immune cell populations in the mesenteric lymph nodes. Therefore, host-microbe interactions might be more complicated than assumed, as bacterial-species adaptations might be highly dependent on the genetic make-up of the individual.
Project description:A dysbiosis in the intestinal microbiome plays a role in the pathogenesis of several immunological diseases. These diseases often show a gender bias, suggesting gender differences in immune responses and in the intestinal microbiome. We hypothesized that gender differences in immune responses are associated with gender differences in microbiota. We demonstrated mouse strain dependent gender differences in the intestinal microbiome. Interestingly, a cluster of colonic genes (related to humoral and cell-mediated immune responses) correlated oppositely with microbiota species abundant in B6 females and in BALB/c males. This suggests that with different genetic backgrounds, gender associated immune responses are differentially regulated by microbiota. The net result was the same, since both mouse strains showed similar gender induced differences in immune cell populations in the mesenteric lymph nodes. Therefore, host-microbe interactions might be more complicated than assumed, as bacterial-species adaptations might be highly dependent on the genetic make-up of the individual.
Project description:The role of environmental factors and gender disparities as determinants of health is incontrovertible. In the digestive sphere, it is noteworthy that one of the most prevalent diseases such as irritable bowel syndrome (IBS) has a predominance in females. The origin of IBS is related to mucosal microinflammation phenomena, psychosocial stress, and in the last years, alterations in gut microbiota. Recent observations from our group in healthy subjects, demonstrate that both chronic psychosocial stress, and female gender per se determine a significant intestinal epithelial barrier dysfunction in response to intercurrent stimuli, which, in susceptible individuals, could result in an early stage in the development of more lasting changes and the onset of clinical manifestations of IBS. Although the intimate mechanisms involved in stress-induced intestinal pathophysiology are not well known, diverse studies suggest that gut microbiota alteration, through epigenetic modifications of the main stress-mediators could be one of them. However, solid scientific evidence demonstrating the influence of stress on gut microbiota and epigenetics of the main stress-mediators is missing. Therefore, we want to investigate and characterize gender-dependent epigenetic modifications involved in intestinal barrier dysfunction in response to acute stress. The identification of gender-dependent abnormal epigenetic patterns related to female gender dysfunction can make a breakthrough in the understanding of the pathophysiology of the regulation of intestinal permeability, and promote positive diagnostic and therapeutic future progress in IBS.
Project description:A striking example of the intricate interplay between diet, microbiota, and host is the effect of inulin, a dietary fiber, on the intestinal epithelium. Ingestion of inulin triggers a wide range of epithelial effects in the colon, such as enhanced proliferation, increased production of mucus and antimicrobial peptides, as well as systemic effects on host metabolism and immune function that are dependent on microbiota-derived molecules. In this study, we investigated the impact of inulin on two critical aspects of diet-microbiota-host interactions: intestinal hypoxia and the modulation of hypoxia-inducible factor (HIF)-1 signaling in intestinal epithelial cells (IECs) in mice colon. To achieve this, we employed a multilayered and multi-omics approach, including dietary interventions, in vitro analysis using intestinal organoids, and both genetic and pharmacological interventions. We found that inulin intake enhances intestinal hypoxia, resulting in the stabilization of HIF-1 in IECs, an effect that is both microbiota- and host-dependent. Our study revealed that HIF-1 plays a key role in regulating IEC proliferation and intestinal stem cell (ISC) function. These changes are associated with HIF-1-dependent metabolic alterations in IECs. Our findings uncover a novel mechanism by which HIF-1 acts in the colon: it acts as a molecular brake, modulating cell proliferation in a microbiota-dependent manner and through metabolic reprogramming, highlighting the complexity of the diet-microbiota-host interactions in the gut.
Project description:Ulcerative colitis (UC), belonging to inflammatory bowel disease (IBD), is a chronic and relapsing inflammatory disorders of the gastrointestinal tract, which is not completely cured so far. Valeriana jatamansi is a Chinese medicine used clinically to treat "diarrhea", which is closely related to UC. This study was to elucidate the therapeutic effects of V. jatamansi extract (VJE) on dextran sodium sulfate (DSS)-induced UC in mice and its underlying mechanism. In this work, VJE effectively ameliorate the symptoms, histopathological scores and reduce the production of inflammatory factors of UC mice. The colon untargeted metabolomics analysis and 16S rDNA sequencing showed remarkable differences in colon metabolite profiles and intestinal microbiome composition between the control and DSS groups, and VJE intervention can reduce these differences. Thirty-two biomarkers were found and modulated the primary pathways including pyrimidine metabolism, arginine biosynthesis and glutathione metabolism. Meanwhile, twelve significant taxa of gut microbiota were found. Moreover, there is a close relationship between endogenous metabolites and intestinal flora. These findings suggested that VJE ameliorates UC by inhibiting inflammatory factors, recovering intestinal maladjustment, and regulating the interaction between intestinal microbiota and host metabolites. Therefore, the intervention of V. jatamansi is a potential therapeutic treatment for UC.
Project description:Commensal microbiota contribute to gut homeostasis and influence gene expression. Intestinal organoid culture closely represent intestinal epithelium and retain intestinal stem cells and dynamic recovery capabilities as well as all major cell types of the intestinal epithelium. We established organoid culture using colon crypts isolated from germ-free (GF), and gnotobiotic mice monocolonized either with the E.coli strain O6K13 (O) or Nissle 1917 strain (N). The expression profiles of these organoids were compared to the organoid culture isolated from conventionally reared (CR) mice in order to disclose genes differentially expressed in response to the change in the intestinal microflora composition.
Project description:Background: Alcohol misuse, binge drinking pattern, and gender-specific effects in the middle-aged population has been clearly underestimated. In the present study, we focused on understanding gender-specific effects of alcohol exposure on the gut-liver axis and the role of gut microbiota in modulating gender-specific responses to alcohol consumption. Methods: Fifty-two-week-old female and male C57BL/6 mice were fasted for 12 h, and then administered a single oral dose of ethanol (EtOH) (6 g/kg). Controls were given a single dose of PBS. Animals were sacrificed 8 h later. Alternatively, fecal microbiota transplantation (FMT) was performed in 52-week-old male mice from female donors of the same age. Permeability of the large intestine (colon), gut microbiota, liver injury, and inflammation was thoroughly evaluated in all groups. Results: Middle-aged male mice exposed to EtOH showed a significant increase in gut permeability in the large intestine, evaluated by FITC-dextran assay and ZO-1, OCCLUDIN and MUCIN-2 immuno-staining, compared to PBS-treated animals, whilst female mice of the same age also increased their gut permeability, but displayed a partially maintained intestinal barrier integrity. Moreover, there was a significant up-regulation of TLRs and markers of hepatocellular injury, cell death (AST, TUNEL-positive cells) and lipid accumulation (ORO) in male mice after EtOH exposure. Interestingly, FMT from female donors to male mice reduced gut leakiness, modified gut microbiota composition, ameliorated liver injury and inflammation, TLR activation and the senescence phenotype of middle-aged mice. Conclusion: Our findings highlighted the relevance of gender in middle-aged individuals who are exposed to alcohol in the gut-liver axis. Moreover, our study revealed that gender-specific microbiota transplantation might be a plausible therapy in the management of alcohol-related disorders during aging.
Project description:There is increasing appreciation for sexually dimorphic effects, but the molecular mechanisms underlying these effects are only partially understood. In the present study, we explored transcriptomics and epigenetic differences in the small intestine and colon of prepubescent male and female mice. In addition, the microbiota composition of the colonic luminal content has been examined. At postnatal day 14, male and female C57BL/6 mice were sacrificed and the small intestine, colon and content of luminal colon were isolated. Gene expression of both segments of the intestine was analysed by microarray analysis. DNA methylation of the promoter regions of selected sexually dimorphic genes was examined by pyrosequencing. Composition of the microbiota was explored by deep sequencing. Sexually dimorphic genes were observed in both segments of the intestine of 2-week-old mouse pups, with a stronger effect in the small intestine. Amongst the total of 349 genes displaying a sexually dimorphic effect in the small intestine and/or colon, several candidates exhibited a previously established function in the intestine (i.e. Nts, Nucb2, Alox5ap and Retnlγ). In addition, differential expression of genes linked to intestinal bowel disease (i.e. Ccr3, Ccl11 and Tnfr) and colorectal cancer development (i.e. Wt1 and Mmp25) was observed between males and females. Amongst the genes displaying significant sexually dimorphic expression, nine genes were histone-modifying enzymes, suggesting that epigenetic mechanisms might be a potential underlying regulatory mechanism. However, our results reveal no significant changes in DNA methylation of analysed CpGs within the selected differentially expressed genes. With respect to the bacterial community composition in the colon, a dominant effect of litter origin was found but no significant sex effect was detected. However, a sex effect on the dominance of specific taxa was observed. This study reveals molecular dissimilarities between males and females in the small intestine and colon of prepubescent mice, which might underlie differences in physiological functioning and in disease predisposition in the two sexes. Small intestine and colon were isolated from two-week old pups of dams fed a low-fat diet and subjected to gene expression profiling