Dietary and commensal derived nutrients: shaping mucosal and systemic immunity.

The intestine serves as the primary site of nutrient absorption in the body while also harboring the highest burden of commensal microflora and representing a major portal of pathogen exposure. As such, the immune network of the intestine relies on both dietary and commensal derived signals to guide appropriate function. Recent advances highlight the role of dietary derived nutrients and commensal derived metabolites in shaping gastrointestinal immunity. In particular, vitamin A has been shown to have dominant and pleiotropic effects in the intestine. In addition, dietary derived AHR ligands and commensal derived metabolites are now emerging as important players in mucosal immunity. Thus nutrition, commensal microflora and the mucosal immune system are all intimately connected.