Oral tolerance, an active immunologic process mediated by multiple mechanisms.

Oral tolerance, the specific suppression of cellular and/or humoral immune responses to an antigen by prior administration of the antigen by the oral route, probably evolved to prevent hypersensitivity reactions to food proteins and bacterial antigens present in the mucosal flora. As with other forms of immunologic tolerance, oral tolerance also provides mechanisms to suppress pathologic reactivity against self and, thus, to prevent or treat autoimmune diseases.