New research into environmental factors of Coeliac Disease
Coeliac Disease is often mistaken or misrepresented as an allergy or intolerance, whilst in fact it is an autoimmune condition triggered by the presence of gluten in the gut.
The exact reasons why our immune system reacts adversely to gluten are still unclear, with many factors proposed, including the effect of different foods, drugs, vaccinations, lifestyle stress and even high hygiene levels.
Recently a new line of research into possible new environmental factors affecting coeliac disease has been published in “Frontiers in Pediatrics” - Microbial Transglutaminase Is Immunogenic and Potentially Pathogenic in Pediatric Celiac Disease by Matthias Torsten and Lerner Aaron.
Food additives in processed food are considered new influencing factors, particularly microbial transglutaminase (mTg). This enzyme is used increasingly by the food industry as a way of improving the quality and shelf life of their products. The authors cite other sources to give examples in the bakery industry where mTg reduces the calorific value of products, improves texture, elasticity and dough characteristics”. According to Professor Lerner at the AESKU KIPP Institute in Germany, one of the co-authors of the publication, the enzyme “functions like the transglutaminase produced by our body”.
Transglutaminase (tTG) is a naturally occurring enzyme that breaks down gluten prior to absorption. In people with Coeliac Disease, the immune system produces antibodies to tTG which reduce the levels of the enzyme. Transglutaminase works in our intestine walls to facilitate absorption of nutrients and the adverse response of our immune system to it results in damage to the walls. This could lead to symptoms such as diarrhoea, malnutrition, constipation and bloating.
The study shows that there is a positive correlation between increasing use of microbial transglutaminase by food industry and the rise in numbers of people with Coeliac Disease over the last 40 years. According to study ‘Several aspects of the mTg hint at its potential pathogenicity and suggest involvement in Coeliac Disease initiation and progression. In sharing functional aspects with the autoantigen…… puts mTg as primary candidate as a partner for Coeliac Disease development’.
Figure 1. mTg sources and chain of events that potentially initiate gluten break of tolerance resulting in CD. (Reprinted from "Microbial Transglutaminase Is Immunogenic and Potentially Pathogenic in Pediatric Celiac Disease" Copyright © 2018 Torsten and Aaron)
Professor Lerner readily admits that there is still further research to be done to confirm their theory. However, there are various published warnings about the potential harmful effects of mTg’s published in Switzerland and Germany. Currently the presence of Microbial transglutaminase is not labelled on food packaging as it is classed as a processing aid rather than a food additive. This may change in the future if the evidence linking the use of mTg with Coeliac Disease grows.
Torsten M and Aaron L (2018) Microbial Transglutaminase Is Immunogenic and Potentially Pathogenic in Pediatric Celiac Disease. Front. Pediatr. 6:389. doi: 10.3389/fped.2018.00389