Fig. 3.

The imbalance between mucosal barriers and gut microbes promotes susceptibility to intestinal inflammation. In the steady state, intestinal bacteria and mucosal barriers maintain a well-balanced relationship, and thus intestinal bacteria and IECs are clearly segregated in the gut. However, dysfunction of mucosal barriers including decreased production of mucin or AMPs due to genetic factors and dysbiosis induced by environmental factors such as high-fat diet or various antibiotics disrupt the well-balanced relationship, and thereby intestinal bacteria can gain access to the gut immune cells, leading to the progression of IBD. IBD: inflammatory bowel disease