Project description:Gut microbiota plays an important role during early development via bidirectional gut- brain signaling. We aimed to explore the potential link between gut microbiota/gut derived metabolites and sympathoadrenal stress responsivity Overall design: The reponse to insulin induced hypoglycemia was compared in normally colonized male mice (control, C) and sterile male (germ free mice, GF) of the same genetic background (C57Bl6) using whole genome transcriptome profyling of adrenal medullary RNA samples.
Project description:Advanced age is associated with chronic low-grade inflammation, which is usually referred to as inflammaging. Elderly are also known to have an altered gut microbiota composition. However, whether inflammaging is a cause or consequence of an altered gut microbiota composition is not clear. In this study gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer immune cell populations in spleen, Peyer’s patches, and mesenteric lymph nodes from conventionalized germ-free mice were analyzed by flow cytometry. In addition, whole-genome gene expression in the ileum was analyzed by microarray. Gut microbiota composition of donor and recipient mice was analyzed with 16S rDNA sequencing. Here we show by transferring aged microbiota to young germ-free mice that certain bacterial species within the aged microbiota promote inflammaging. This effect was associated with lower levels of Akkermansia and higher levels of TM7 bacteria and Proteobacteria in the aged microbiota after transfer. The aged microbiota promoted inflammation in the small intestine in the germ-free mice and enhanced leakage of inflammatory bacterial components into the circulation was observed. Moreover, the aged microbiota promoted increased T cell activation in the systemic compartment. In conclusion, these data indicate that the gut microbiota from old mice contributes to inflammaging after transfer to young germ-free mice. Overall design: Gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer whole-genome gene expression in the distal ileum was analyzed by microarray.
Project description:Gut microbiota dysbiosis characterizes systemic metabolic alteration, yet its causality is debated. To address this issue, we transplanted antibiotic-free conventional wild-type mice with either dysbiotic (“obese”) or eubiotic (“lean”) gut microbiota and fed them either a NC or a 72%HFD. We report that, on NC, obese gut microbiota transplantation reduces hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-transplanted mice. Of note, this phenotype is blunted in conventional NOD2KO mice. By contrast, lean microbiota transplantation did not affect hepatic gluconeogenesis. In addition, obese microbiota transplantation changed both gut microbiota and microbiome of recipient mice. Interestingly, hepatic gluconeogenesis, PEPCK and G6Pase activity were reduced even once mice transplanted with the obese gut microbiota were fed a 72%HFD, together with reduced fed glycaemia and adiposity compared to non-transplanted mice. Notably, changes in gut microbiota and microbiome induced by the transplantation were still detectable on 72%HFD. Finally, we report that obese gut microbiota transplantation may impact on hepatic metabolism and even prevent HFD-increased hepatic gluconeogenesis. Our findings may provide a new vision of gut microbiota dysbiosis, useful for a better understanding of the aetiology of metabolic diseases. all livers are from NC-fed mice only. Overall design: 6-wk-old C57Bl/6 male mice were fed a normal chow (NC) for 4 weeks. Mice have been transplanted with the vehicle (reduced PBS), or lean or obese gut microbiota. At the sacrifice by cervical dislocation, livers were dissected and snap-frozen in liquid nitrogen per each mouse.
Project description:Antibiotics have long-lasting consequences on the gut microbiota with the potential to impact host physiology and health. However, little is known about the transgenerational impact of an antibiotic-perturbed microbiota. Here we demonstrated that adult pregnant female mice inoculated with a gut microbial community shaped by antibiotic exposure passed on their dysbiotic microbiota to their offspring. This dysbiotic microbiota remained distinct from controls for at least 5 months in the offspring without any continued exposure to antibiotics. By using IL-10 deficient mice, which are genetically susceptible to colitis, we showed mice that received an antibiotic-perturbed gut microbiota from their mothers had increased risk of colitis. Taken together, our findings indicate that the consequences of antibiotic exposure affecting the gut microbiota can extend to a second generation. Overall design: C57BL/6 or IL10 deficient pups were born to mothers who were exposed to Control or STAT-perturbed cecal contents. (N = 3/group)
Project description:Familial Mediterranean fever (FMF) is an inflammatory genetic disease characterized by elevated systemic reactivity against commensal gut microbiota and high levels of gut Candida albicans. The current study investigated the effects of Lactobacillus acidophillus INMIA 9602 Er 317/402 strain (probiotic “Narine”) on the relative abundance of gut enteric bacteria, lactobacilli, Staphylococcus aureus, and Enteroccocus faecalis in Candida albicans-carrier and non-carrier FMF patients in remission with the main MEFV mutation patterns M694V/V726A- the prevalent MEFV gene mutation within FMF patients in the Armenian cohort. Our data revealed that M694V/V726A mutations in PURIN inflammasome leading to FMF disease brought to gender specific differences in microbial community structure in FMF patients. Possibly, long-term colchicine use suppresses the PURIN inflammasome/inhibits NLRP3 inflammasome-dependent IL-1β release influencing on overgrowth of C. albicans in gut microbiota of FMF patients. The comparison of Operational Taxonomic Units (OTUs) of enteric bacteria in C. albicans-carrier and non-carrier female patients revealed the statistically significant increase in OTUs of enterobacteria in C. albicans-carriers. In contrast to this, there were no differences in abundance of Enteroccocus faecalis between female FMF C. albicans-carriers compared with non-carriers, while male FMF C. albicans-carriers have increased abundance of E. faecalis in their gut microbiota compared with that of male patients with none carriers. The gut microbiota of FMF patients (both male and female) with C. albicans below baseline level contains high abundance of lactobacilli compared with C. albicans-carriers. The adoption of Lactobacillus acidophilus INMIA 9602 Er 317/402 leads to changes in gut microbiota composition of FMF patients. It reduces, in particularly, the abundance of enterobacteria in females, and Enteroccocus faecalis in men parallel with reducing the numbers of yeast in gut microbiota of FMF patients. We hypothesize that colchicine treatment changes the already-altered gut microbiota of FMF patients, thereby affecting the regulation of immune system by inhibition of NLRP3 inflammasome. Colchicine could lead to overgrowth of C. albicans in gut microbiota of FMF patients, whereas the Lactobacillus acidophilus INMIA 9602 Er 317/402 works on activation of inflammasome by new changes in gut microbiota of patients. Overall design: 166 samples, patients diagnosed with Familial Mediterranean Fever were given either placebo or treated with Narine or Colibacteron. The human fecal metagenome was analyzed pre- and post-treatment. Please note that the array probe sequences are under patent therefore no CDF or probe mapping file is available.
Project description:Irritable Bowel Syndrome (IBS) is a disorder of the gut-brain axis, characterized by altered gut function and frequent psychiatric co-morbidity. Although altered intestinal microbiome profiles have been documented, their relevance to the clinical expression of IBS is unknown. To evaluate a functional role of the microbiota, we colonized germ-free mice with fecal microbiota from healthy controls or IBS patients with accompanying anxiety, and monitored gut function and behavior. Mouse microbiota profiles clustered according to their human donors. Despite having taxonomically similar composition as controls, mice with IBS microbiota had distinct serum metabolomic profiles related to neuro- and immunomodulation. Mice with IBS, but not control microbiota, exhibited faster gastrointestinal transit, intestinal barrier dysfunction, innate immune activation and anxiety-like behavior. These results support the notion that the microbiota contributes to both intestinal and behavioral manifestations of IBS and rationalize the use of microbiota-directed therapies in ameliorating IBS. Overall design: We extracted total RNA of colonic tissues extracted from germ-free NIH swiss mice (10-12 weeks) colonized with healthy human gut microbiota (10 mice per fecal sample, 5 fecal samples, total=50 mice), and mice colonized with human microbiota of IBS patients (10 mice per sample, 6 fecal samples, total =60 mice). We then pooled together all the RNA samples of all the mice colonized with the same microbiota, to form a representative sample for the colonization with that specific human fecal sample. We finally ran 11 samples in total through the NanoString nCounter® Gene Expression CodeSet for mouse inflammation genes.
Project description:The mammalian gut harbors a diverse microbial community (gut microbiota) that mainly consists of bacteria. Their combined genomes (the microbiome) provide biochemical and metabolic functions that complement host physiology. Maintaining symbiosis seems to be a key requirement for health as dysbiosis is associated with the development of common diseases. Previous studies indicated that the microbiota and the host’s epithelium signal bidirectional inducing transcriptional responses to fine-tune and maintain symbiosis. However, little is known about the host’s responses to the microbiota along the length of the gut as earlier studies of gut microbial ecology mostly used either colonic or fecal samples. This is of importance as not only function and architecture of the gut varies along its length but also microbial distribution and diversity. Few recent studies have begun to investigate microbiota-induced host responses along the length of the gut. However, these reports used whole tissue samples and therefore do not allow drawing conclusions about specificity of the observed responses. Which cells in the intestinal tissue are responsible for the microbially induced response: epithelial, mesenchymal or immune cells? Where are the responding cells located? Furthermore, the gut microbiota has been implicated in epigenetic regulation of the host’s transcriptional profile. We used using extensive microarray analysis of laser capture microdissection (LCM) harvested ileal and colonic tip and crypt fractions from germ-free mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) to investigate the microbiota-induced transcriptional responses and their kinetics in specific and well-defined cell populations of the host’s epithelium. Ileum and colon segments were dissected from germ-free 10-12 weeks old female C57Bl/6 mice and on day 1, 3, 5 and 7 after colonization, washed and frozen as OCT blocks. Cryosections were prepared from these OCT blocks and tip/crypt fractions isolated using laser capture microdissection. To investigate the microbiota-induced transcriptional responses specific for specific subpopulations of intestinal epithelial cells and their kinetics, tip and crypt fractions of ileal and colonic epithelium of germ-free 10-12 weeks old female C57Bl/6 mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) were harvested using laser capture microdissection and probed in an extensive microarray analysis.
Project description:Chronic acid suppression by proton pump inhibitor (PPI) has been hypothesized to alter the gut microbiota via a change in intestinal pH. To evaluate the changes in gut microbiota composition by long-term PPI treatment. Twenty-four week old F344 rats were fed with (n = 5) or without (n = 6) lansoprazole (PPI) for 50 weeks. Then, profiles of luminal microbiota in the terminal ileum were analyzed. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX (454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics.
Project description:Despite accepted health benefits of dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic model, in which mice were colonized with a synthetic human gut microbiota, we elucidated the functional interactions between dietary fiber, the gut microbiota and the colonic mucus barrier, which serves as a primary defence against pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation promoted greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium, but only in the presence of a fiber-deprived microbiota that is pushed to degrade the mucus layer. Our work reveals intricate pathways linking diet, gut microbiome and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Germ-free mice (Swiss Webster) were colonized with synthetic human gut microbiota comprising of 14 species belonging to five different phyla (names of bacterial species: Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides caccae, Bacteroides uniformis, Barnesiella intestinihominis, Eubacterium rectale, Marvinbryantia formatexigens, Collinsella aerofaciens, Escherichia coli HS, Clostridium symbiosum, Desulfovibrio piger, Akkermansia muciniphila, Faecalibacterium prausnitzii and Roseburia intestinalis). These mice were fed either a fiber-rich diet or a fiber-free diet for about 6 weeks. The mice were then sacrificed and their cecal tissues were immediately flash frozen for RNA extraction. The extracted RNA was subjected to microarray analysis based on Mouse Gene ST 2.1 strips using the Affy Plus kit. Expression values for each gene were calculated using robust multi-array average (RMA) method. Overall design: Fiber-rich diet group contained 4 replicate mice (2 independent experiments) and Fiber-free diet group contained 3 replicate mice (2 independent experiments)
Project description:Chronic diseases arise when pathophysiological processes achieve a steady state by self-reinforcing. Here, we explored the possibility of a self-reinforcement state in a common condition, chronic constipation, where alterations of the gut microbiota have been reported. The functional impact of the microbiota shifts on host physiology remains unclear, however we hypothesized that microbial communities adapted to slow gastrointestinal transit affect host functions in a way that reinforces altered transit, thereby maintaining the advantage for microbial self-selection. To test this, we examined the impact of pharmacologically (loperamide)-induced constipation (PIC) on the structural and functional profile of altered gut microbiota. PIC promoted changes in the gut microbiome, characterized by decreased representation of butyrate-producing Clostridiales, decreased cecal butyrate concentration and altered metabolic profiles of gut microbiota. PIC-associated gut microbiota also impacted colonic gene expression, suggesting this might be a basis for decreased gastrointestinal (GI) motor function. Introduction of PIC-associated cecal microbiota into germ-free (GF) mice significantly decreased GI transit time. Our findings therefore support the concept that chronic diseases like constipation are caused by disease-associated steady states, in this case, caused by reciprocating reinforcement of pathophysiological factors in host-microbe interactions. We used microarrays to detail the global gene expression profile in the proximal colon smooth muscle tissues of germ-free, conventionalized, or specific pathogen free mouse C57Bl/6 female and male specific pathogen free (SPF) mice were bred and housed in the animal care facility at the University of Chicago. Mice of 8–10 weeks of age were treated with 0.1% loperamide in the drinking water for 7 days. Age matched, germ-free (GF) C57Bl/6 mice were gavaged orally with cecal luminal contents harvested from control or loperamide-treated C57Bl/6 donor mice. Recipient mice were sacrificed 4 weeks post-colonization.