Fig 1.

Theoretical mechanism of action for hydrolyzed diets. Normal dietary protein (upper panel) is degraded into peptides, some of which are immunogenic. These immunogenic peptides are taken up by antigen processing cells in the gastrointestinal mucosa and presented on the major histocompatibility complex (MHC), leading to immune reactions, dietary intolerances, or allergy. In the partially hydrolyzed diets (lower panel), the dietary protein has been partially degraded before consumption, with the proteins broken down into small peptides that are not processed and presented as effectively, thus reducing immune response against the diet.