Microbial transglutaminase should be considered as an environmental inducer of celiac disease

Abstract

Due to the recent interest in food additives that can act as triggering factors in autoimmune diseases including celiac disease (CD), the present letter to the editor expands on the microbial transglutaminase (mTG). It is heavily consumed by a plethora of food processing industries as “glue of proteins” thus improving product’s stability, texture and shelf life. However, more and more information is accumulated lately, questioning its safety. Its cross-linked gliadin complexes are immunogenic in CD. The enzyme increases gliadin uptake, is transported in a trans-epithelial way and deposited below the enterocyte’s line, has anti- phagocytic activity, enhances intestinal permeability and creates luminal resistant isopeptide bonds. No doubt that mTG is beneficial to food industries but a caveat to public health is highly recommended.

Keywords: Microbial transglutaminase; Transglutaminase 2; Celiac disease; Processed food; Food additive; Food industry; Immunogenicity; Pathogenicity; Food safety; Public health

Core tip: Recently, various food additives were suspected to trigger autoimmunity, including celiac disease (CD). Microbial transglutaminase (mTG), a heavily used one that imitates functionally the autoantigen of CD is a prime environmental candidate to induce the disease. The enzyme increases gliadin uptake, is transported in a trans-epithelial way, has anti- phagocytic activity, enhances intestinal permeability and creates luminal resistant isopeptide bonds. Its gliadin cross-linked complexes are immunogenic and reflect the degree of intestinal injury in CD patients. The present letter updates and explains why the protein linker, mTG, is beneficial to food industries but a caveat to public health.