Fig. 3.

Factors affecting the intestinal environment: a working hypothesis.

A simplified model: Three factors, innate immunity, microbiota and food, cross talk with each other and contribute to the intestinal environment in both the short and long term. Innate Immunity: Paneth cell α-defensins act as major effectors in innate immunity. Microbiota: Commensal bacteria form the normal intestinal microbiota. Food (dietary factors): Food and dietary factors act as orally administered extrinsic factors.