The role of the gut mucosal immunity in the development of tolerance versus development of allergy to food

Purpose of review To provide an overview on the role of gut mucosal immunity in the development of tolerance to food versus allergy to food. Recent findings The gastrointestinal tract, through innate and specific immunologic factors, acts as a defense against ingested antigens. In addition to the mucous membrane integrity and the digestion, numerous specific immunologic cells and mediators orchestrate such defensive mechanisms. In case of food antigens, the outcome is usually in favor of tolerance. Defects in that barrier, however, can lead to the development of aberrant immunologic responses, including hypersensitivity reactions. Summary The prevailing evidence is that healthy mucosal immunity plus appropriate feeding regimen during early infancy are in favor of food tolerance. However, in addition to genetic predisposition, development of allergy is facilitated by defects in the gut barrier (immune or nonimmune) and the food allergen load.