Although we were not aware of a systematic study investigating whether there is a difference between the abilities of allergens and other proteins of plant sources in surviving the digestive systems of allergic and control subjects, it is known that IgE may be present in the gut in food allergy patients [214], and a portion of two ingested food allergens of animal sources (Bos d 5, Gal d 2) is absorbed and transported throughout the body in an antibody-reactive form including through the gut of control subjects [215]. Here, IGHE is linked to food allergy.