Project description:Dysbiosis of the gut microbiota has been linked to disease pathogenesis in type 1 diabetes (T1D), yet the functional consequences to the host of this dysbiosis is unknown. Here, we have performed a metaproteomic analysis of 103 stool samples from subjects that either had recent-onset T1D, were high-risk autoantibody positive or low-risk autoantibody negative relatives of individuals with beta cell autoimmunity or healthy individuals to identify signatures in host and microbial proteins associated with disease risk. Multivariate modelling analysis demonstrated that both human host proteins and microbial derived proteins could be used to differentiate new-onset and seropositive individuals from low-risk and healthy controls. Significant alterations were identified between subjects with T1D or islet autoimmunity versus autoantibody negative and control subjects in the prevalence of individual host proteins associated with exocrine pancreas function, inflammation and mucosal function. Data integrationIntegrative analysis combining the metaproteomic data with bacterial abundance showed that taxa that were depleted in new-onset T1D patients were positively associated with host proteins involved in maintaining function of the mucous barrier, microvilli adhesion and exocrine pancreas. These data support the notion that T1D patients have increased intestinal inflammation and decreased barrier function. They also confirmed that pancreatic exocrine dysfunction occurs in new-onset T1D patients and show for the first time that this dysfunction is present in high-risk individuals prior to disease onset. Our data has identified a unique T1D-associated signature in stool that may be useful as a means to monitor disease progression or response to therapies aimed at restoring a healthy microbiota.
Project description:We purified the intestinal epithelial cells from biopsies taken from the ileum and colon of a paediatric cohort of IBD patients and healthy controls
Project description:Arginase 1 (Arg1), which converts L-arginine into ornithine and urea, exerts pleiotropic immunoregulatory effects. Patients with inflammatory bowel disease (IBD) show an enhanced expression and activity of Arg1 in the intestinal (sub-)mucosa, but the function of Arg1 in IBD remains poorly characterized. Here, we found that Arg1 expression correlates with the degree of inflammation in colitic tissues of IBD patients. In mice with - experimental colitis Arg1 was upregulated in an IL-4-/IL-13- and intestinal microbiota-dependent manner. Tie2-Cre+/-Arg1fl/fl mice lacking Arg1 in hematopoietic and endothelial cells recovered faster from colitis than Arg1-expressing littermates. This correlated with decreased vessel density, compositional changes in the intestinal microbiota, diminished infiltration by myeloid cellsand an accumulation of intraluminal polyamines that are associated with epithelial healing. Dietary L-arginine restriction abolished the protective effect of Arg1-deletion, suggesting that protection is related to an increased availability of L-arginine. Fecal microbiota transfers from Tie2-Cre+/-Arg1fl/fl mice into wildtype recipients restored the protective, anti-inflammatory phenotype while transfers from wildtype littermates into Arg1-deficient mice prevented the accelerated recovery from colitis. Thus, altered intestinal microbiota and metabolic products in Tie2-Cre+/-Arg1fl/fl mice account for the accelerated resolution from colitis in the absence of Arg1. Subsequently, L-arginine serves as novel therapeutic and diagnostic target for clinical intervention in IBD patients.
Project description:Aim: To compare the overall transcriptional profile in healthy controls and celiac disease patients. This dataset, was used to evaluate if our in vitro model (intestinal intraepithelial lymphocytes, desccribed in doi:10.1016/j.jaut.2020.10242 ) is representative of the transcriptional profile in the intestine under healthy or inflammatory conditions. Samples: Upper colonoscopy biopsies from 5 control and 11 celiac disease patients were taken, total RNA was extracted and RNA-sequencing was performed (without replicates)
Project description:Abdominal and pelvic radiotherapy (RT) reduces the renewal capacity of the epithelium. Rectal biopsies obtained from patients receiving pelvic RT have revealed atrophy of surface epithelium, acute cryptitis, crypt abscesses, crypt distortion and atrophy, and stromal inflammation. Modifications in intestinal microbiota, such as an increase in the number of pathogens, may contribute to intestinal injury. The prebiotic effect of a carbohydrate is assessed by its capacity to stimulate the proliferation of healthy bacteria (Bifidobacterium, Lactobacillus) rather than pathogenic bacteria (Clostridium, E. coli).
The hypothesis of the study is that a mixture of inulin and fructooligosaccharide could modulate Lactobacillus and Bifidobacterium and reduce the intestinal injury in patients affected of gynaecological cancer and treated with abdominal radiotherapy.
Project description:Application of a mass spectrometry -based approach to assess the gut microbiota composition and the associated metaproteomic functionality in patients with intestinal COVID-19 infection
Project description:Intestinal microbial dysbiosis is associated with Crohn’s disease (CD). However, the mechanisms leading to the chronic mucosal inflammation that characterizes this disease remain unclear. To evaluate causality and mechanisms of disease, we conducted a systems level study of the interactions between the gut microbiota and host in new-onset pediatric patients. We report an altered host proteome in CD patients indicative of impaired mitochondrial functions. A downregulation of mitochondrial proteins implicated in H2S detoxification was observed, while the relative abundance of H2S microbial producers was increased. Network correlation analysis identified Atopobium parvulum as the central hub of H2S producers. Gnotobiotic and conventionalized colitis-susceptible interleukin-10-deficient (Il10-/-) mice demonstrated that A. parvulum induced colitis, a phenotype requiring the presence of the intestinal microbiota. Administration of bismuth, a H2S scavenger, prevented A. parvulum-induced colitis in Il10-/- mice. This study identified host-microbiota interactions that are disturbed in CD patients providing mechanistic insights on CD pathogenesis.