Project description:Alterations in intestinal microbiota and intestinal short chain fatty acids profiles have been associated with the pathophysiology of obesity and insulin resistance. Whether intestinal microbiota dysbiosis is a causative factor in humans remains to be clarified We examined the effect of fecal microbial infusion from lean donors on the intestinal microbiota composition, glucose metabolism and small intestinal gene expression. Male subjects with metabolic syndrome underwent bowel lavage and were randomised to allogenic (from male lean donors with BMI<23 kg/m2, n=9) or autologous (reinfusion of own feces, n=9) fecal microbial transplant. Insulin sensitivity and fecal short chain fatty acid harvest were measured at baseline and 6 weeks after infusion. Intestinal microbiota composition was determined in fecal samples and jejunal mucosal biopsies were also analyzed for the host transcriptional response. Insulin sensitivity significantly improved six weeks after allogenic fecal microbial infusion (median Rd: from 26.2 to 45.3 μmol/kg.min, p<0.05). Allogenic fecal microbial infusion increased the overall amount of intestinal butyrate producing microbiota and enhanced fecal harvest of butyrate. Moreover, the transcriptome analysis of jejunal mucosal samples revealed an increased expression of genes involved in a G-protein receptor signalling cascade and subsequently in glucose homeostasis. Lean donor microbial infusion improves insulin sensitivity and levels of butyrate-producing and other intestinal microbiota in subjects with the metabolic syndrome. We propose a model wherein these bacteria provide an attractive therapeutic target for insulin resistance in humans. (Netherlands Trial Register NTR1776).
Project description:Instability in the composition of gut bacterial communities, referred as dysbiosis, has been associated with important human intestinal disorders such as Crohn’s disease and colorectal cancer. Here, we show that dysbiosis coupled to Nod2 or Rip2 deficiency suffices to cause an increased risk for intestinal inflammation and colitis-associated carcinogenesis in mice. Aggravated epithelial lesions and dysplasia upon chemical-induced injury associated with loss of Nod2 or Rip2 can be prevented by antibiotics or anti-IL6R treatment. Nod2-mediated risk for intestinal inflammation and colitis-associated tumorigenesis is communicable through maternally-transmitted microbiota even to wild-type hosts. Disease progression was identified to drive complex NOD2-dependent changes of the colonic-associated microbiota. Reciprocal microbiota transplantation rescues the vulnerability of Nod2-deficient mice to colonic injury. Altogether, our results unveil an unexpected function for NOD2 in shaping a protective assembly of gut microbial communities, providing a rationale for intentional manipulation of genotype-dependent dysbiosis as a causative therapeutic principle in chronic intestinal inflammation.
Project description:Instability in the composition of gut bacterial communities, referred as dysbiosis, has been associated with important human intestinal disorders such as CrohnM-bM-^@M-^Ys disease and colorectal cancer. Here, we show that dysbiosis coupled to Nod2 or Rip2 deficiency suffices to cause an increased risk for intestinal inflammation and colitis-associated carcinogenesis in mice. Aggravated epithelial lesions and dysplasia upon chemical-induced injury associated with loss of Nod2 or Rip2 can be prevented by antibiotics or anti-IL6R treatment. Nod2-mediated risk for intestinal inflammation and colitis-associated tumorigenesis is communicable through maternally-transmitted microbiota even to wild-type hosts. Disease progression was identified to drive complex NOD2-dependent changes of the colonic-associated microbiota. Reciprocal microbiota transplantation rescues the vulnerability of Nod2-deficient mice to colonic injury. Altogether, our results unveil an unexpected function for NOD2 in shaping a protective assembly of gut microbial communities, providing a rationale for intentional manipulation of genotype-dependent dysbiosis as a causative therapeutic principle in chronic intestinal inflammation. Analysis used RNA extracted from colonic mucosa of untreated, antibiotics-treated or metronidazole-treated C57Bl/6J and Nod2-deficient mice in CAC model. Direct comparisons were performed as follow: C57Bl/6J untreated mice vs Nod2-deficient untreated mice, C57Bl/6J antibiotics-treated mice vs Nod2-deficient antibiotics-treated mice, C57Bl/6J metronidazole-treated mice vs Nod2-deficient metronidazole-treated mice, C57Bl/6J untreated mice vs C57Bl/6J antibiotics-treated mice, C57Bl/6J untreated mice vs C57Bl/6J metronidazole-treated mice, Nod2-deficient untreated mice vs Nod2-deficient antibiotics-treated mice, Nod2-deficient untreated mice vs Nod2-deficient metronidazole-treated mice. Indirect comparisons with control data were made across multiple arrays with raw data pulled from different channels for data analysis.
Project description:Gut dysbiosis is closely involved in the pathogenesis of inflammatory bowel disease (IBD). However, it remains unclear whether IBD-associated gut dysbiosis plays a primary role in disease manifestation or is merely secondary to intestinal inflammation. Here, we established a humanized gnotobiotic (hGB) mouse system to assess the functional role of gut dysbiosis associated with two types of IBD - Crohn's disease (CD) and ulcerative colitis (UC). In order to explore the functional impact of dysbiotic microbiota in IBD patients on host immune responses, we analyzed gene expression profiles in colonic mucosa of hGB mice colonized with healty (HC), CD, and UC microbiota.
Project description:Morphine causes microbial dysbiosis. In this study we focused on restoration of native microbiota in morphine treated mice and looked at the extent of restoration and immunological consequences of this restoration. Fecal transplant has been successfully used clinically, especially for treating C. difficile infection2528. With our expanding knowledge of the central role of microbiome in maintenance of host immune homeostasis17, fecal transplant is gaining importance as a therapy for indications resulting from microbial dysbiosis. There is a major difference between fecal transplant being used for the treatment of C. difficile infection and the conditions described in our studies. The former strategy is based on the argument that microbial dysbiosis caused by disproportionate overgrowth of a pathobiont can be out-competed by re-introducing the missing flora by way of a normal microbiome transplant. This strategy is independent of host factors and systemic effects on the microbial composition. Here, we show that microbial dysbiosis caused due to morphine can be reversed by transplantation of microbiota from the placebo-treated animals.
Project description:Enterococcus faecalis is a natural inhabitant of the human gastrointestinal tract. In a healthy physiological state of the gut (eubiosis), E. faecalis is a subdominant species in the intestinal microbiota. When the intestinal homeostasis is disrupted (dysbiosis), it becomes dominant species and can cause infections. The taurocholate bile acid (TCA) becomes prominent during dysbiosis. This experiment aimed to better understand how E. faecalis adapts to TCA. We showed that TCA reprograms genes involved in the pool management of amino acids and nucleotides.
Project description:The gut microbiota plays an important role in host health. Microbiota dysbiosis has been implicated in the global epidemic of Metabolic Syndrome (MetS) and could impair host metabolism by noxious metabolites. It has been well established that the gut microbiota is shaped by host immune factors. However, the effect of T cells on the gut microbiota is yet unknown. Here, we performed a metagenomic whole-genome shotgun sequencing (mWGS) study of the microbiota of TCRb-/- mice, which lack alpha/beta T cells.
Project description:Colorectal cancer (CRC) is closely related to gut dysbiosis. We investigated the effects of imbalanced gut microbiota on the progression of intestinal adenoma in Apcmin/+ mice model using fecal microbiota transplantation (FMT). Administration of feces from CRC patients increased tumor proliferation and decreased apoptosis in tumor cells. Abnormal expression of genes related to Wnt-protein binding and lipid metabolic process was observed.
Project description:The goal of this project is to find out whether human intestinal IgA1 and IgA2 secretion, transport and reactivity towards the microbiota might be involved in dysbiosis induction during Crohn’s disease and Ulcerative colitis. Mass spectrometry was used to characterize SIgA from Crohn’s disease patient and Ulcerative colitis patient, in term of O- and N-glycosylation in order to study their reverse transcytosis capacity and their role in intestinal inflammation.