Project 467200

Inflammatory bowel disease (IBD) is a debilitating chronic disorder that targets the gastrointestinal (GI) tract. Although the cause remains unknown, recent studies have identified the association between changes in our gut microbiota and IBD inflammation. While most gut bacteria are essential for our GI health, pathobionts are bacteria that induce GI inflammation and are highly abundant in IBD patients.IBD patients undergo routine endoscopies which require the administration of laxative-based bowel prep to clear out the GI tract for the endoscope. It is common that after bowel prep, IBD patients experience inflammatory flare-ups. I hypothesize that pathobionts that are associated with inflammation preferentially survive bowel prep and trigger GI inflammation in IBD patients. I will study the survival of pathobionts during bowel prep treatment by measuring their growth in laxatives compared to commensal bacteria. I will analyze the genome sequence of the pathobionts and identify genes that could contribute to the pathobiont's survival during bowel prep to predict the pathobiont response in a laboratory setting. I will then measure their response in a mouse model of bowel prep. I will inoculate pathobionts into mice and administer bowel prep. I will measure the extent of colonic inflammation and the changes in the mouse gut microbiota by sequencing mouse stool samples to determine the levels of colonized pathobionts compared to commensal bacteria. By monitoring pathobiont changes during and after bowel prep, this study will provide insight as to how pathobionts play a role in GI inflammation after bowel prep in IBD. More importantly, identifying the impact of pathobionts and inflammation can help determine more efficient endoscopy regimes for IBD patients.