Role of Bile Acids and Microbiota in Clostridioides Difficile Infection in Ulcerative Colitis

Ulcerative Colitis (UC) is a chronic Inflammatory Bowel Disease characterized by chronic inflammation of the colon. Composition of gut microbiota of UC patients is abnormal (dysbiosis). Ulcerative Colitis patients have an increased risk of Clostridioides difficile infection (CDI) and CDI complications (colectomy, death, recurrence). The reason for this increased risk in IBD patients is not fully understood. The decrease in the proportion of secondary bile acids, induced by microbiota dysbiosis in patients with UC could favor C. difficile infection. The main objective of the study is to describe the composition of bile acids (primary and secondary) in children followed for UC during relapse with or without CDI and to compare it to children with UC in remission and healthy controls. The composition of fecal microbiota will be also describe to correlate dysbiosis and bile acid abnormalities. And finally some fecal biomarkers will be study : short chain fatty acids, metabolic pathway of Tryptophan, and fecal Calprotectin.