Non-IgE/Mixed Food Allergies and Functional Gastrointestinal Disorder: A Common Thread between Childhood and Adulthood

Adverse food reactions (AFRs) are abnormal clinical responses related to food or the ingestion of a food component, including drinks, food additives, and dietary supplements . AFRs can be classified as intolerances (non-immuno-mediated) or allergies (immune-mediated) depending on the pathophysiological mechanism of action. Food intolerances are adverse responses to a food component in which the human immune system does not play a direct role, are often dose-dependent, and are not consistently reproducible. They can be caused by several mechanisms, such as the peculiar properties of an ingested food (i.e., toxic or pharmacologic active component, such as caffeine or alcohol), the lack of a particular enzyme with which to digest nutrients, or nutrients being too abundant to be completely digested.