Evaluation of Food Specific Immunoglobulin G (IgG)-Guided Exclusion Diet in the Treatment of Irritable Bowel Syndrome and Inflammatory Bowel disease

Abstract

From the beginning of this century, symptomatic improvements in different disorders with food specific immunoglobulin G (IgG)-guided exclusion diet have been reported. Most of them belong to gastrointestinal tract such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Although this diet has given a chance of symptomatic improvement as the main treatment in IBS or adjuvant therapy in IBD, it is still a matter of debate. Presence of food specific IgG antibodies also in healthy individuals and the use of IgG4 antibodies, known as protective antibodies against excessive immune responses in some of these studies are the main causes of these controversies. Additionally, there is no definite nomenclature for the reaction mediated by food specific IgG antibodies, the name of food intolerance is often used and it makes confusion by evoking non-immune adverse food reactions. Finally, the underlying mechanisms of these improvements have not been fully elucidated yet. Removal of foods that cause intensive immune responses or non-IgE-mediated allergic reactions or increased mast cell activation through IgG-food antigen complexes are among the suggested mechanisms. The effectiveness of this diet, opposing views and possible mechanisms to explain symptomatic improvements are focused in this manuscript