The study involves characterizing the microbiota of patients with IBS, functional diarrhea, IBD, severe motility disorders and celiac disease.

This will be complemented by a translational phase of human-mouse hybrid experiments in which germ-free mice will be colonized with feces from these patients with different GI disease and non-disease controls and we will compare symptoms, microbiota composition and histological changes in the gut and in the brain of the mice.

A complex community of microbes collectively referred to as microbiota, inhabit the human body. The intestinal microbiota is a diverse and dynamic ecosystem, which has developed a mutualistic relationship with its host and plays a crucial role in the development of the host's innate and adaptive immune responses. This ecosystem serves the host by protecting against pathogens, harvesting otherwise inaccessible nutrients, aiding in neutralization of drugs and carcinogens, and affecting the metabolism of lipids. Gut bacteria modulate intestinal motility, barrier function and visceral perception. A better understanding of the role of microbiota in the proposed GI diseases will have profound impact in the characterization of future biomarkers and has also potential treatment implications. As the microbiota may be disturbed in the mentioned GI conditions, a possible treatment approach could be to correct dysbiosis either by the administration of an antibiotic or a preparation of 'beneficial' bacteria (probiotics) according to each bacteria profile.

General Objective The objective of this study is to identify different patterns of intestinal microbiota in patients diagnosed with inflammatory bowel disease, microscopic colitis, functional diarrhea, severe motility disorders, celiac disease and irritable bowel syndrome and to compare it with non-disease controls, by assessing data (questionnaires) and samples (stool, blood and tissue) from single time point (endoscopy/colonoscopy appointment).

Inclusion Criteria:

• Diagnosis of IBD, active celiac disease (aTTG positive + endoscopic view and histological findings compatible), IBS (Rome IV criteria or physician diagnosis) severe motility disorders (severe constipation, severe functional dyspepsia) gluten sensitivity (IBS diarrhea predominant with positive anti gliadin antibodies and negative aTTG), functional diarrhea (Rome IV criteria), anal fissure and/or fistula or non-disease control individual or 1st degree family member of celiac patient.
• Willingness to participate
• Signed Informed Consent

Exclusion Criteria:

• Antibiotics in the last month
• Probiotics in the previous month

A cohort of 260 patients of either sex between 18 and 75 years of age consulting to either the GI Clinical Investigation, the Endoscopy Unit (McMaster University Endoscopy Centre)