Gut Homeostasis Breakdown in Inflammatory Bowel Disease

Abstract

In the gut, where tremendous numbers of bacteria exist, the epithelial barrier of intestinal epithelial cells regulates gut bacteria by either chemical barriers, such as bacteriocidal molecules in the small intestine, or physical barriers such as mucins in the large intestine. The control of gut bacteria by the epithelial barrier is required for the maintenance of gut homeostasis. That is why disruption of the balance between gut bacteria and the epithelial barrier, due to a change in microbial composition or dysfunction of the barrier system resulting from a genetic predisposition, leads to inflammatory bowel diseases elicited by excessive immune responses to gut bacteria.