Up to five percent of all people who eat wheat products suffer from wheat sensitivities. These are immunological responses to wheat and related cereals such as spelt, rye, and barley, and include celiac disease, wheat allergy, and non-celiac-non allergy wheat sensitivity (NCWS). This can cause physical symptoms as diverse as diarrhea, fatigue, psychological disorders, and worsening of chronic inflammatory diseases. Certain proteins in wheat are the cause. Now doctors and biomedical and agricultural researchers at Johannes Gutenberg University Mainz (JGU) and the University of Hohenheim have joined forces to study these disorders, especially NCWS. Their findings may contribute to the breeding of new types of wheat that lack these disease causing properties while maintaining the characteristics appreciated in wheat products.
The disorder termed NCWS has long posed a riddle to physicians and science. It apparently affects a large number of people when they eat wheat-based foods. The cause is an innate immune response that is triggered by wheat proteins called alpha-amylase-trypsin inhibitors (ATIs). “It is important to differentiate between NCWS, celiac disease, and wheat allergy,” emphasized project coordinator Professor Detlef Schuppan, gastroenterologist, biochemist, and immunologist, head of the Institute of Translational Immunology at the University Medical Center of Johannes Gutenberg University Mainz. “Celiac disease is well defined and relatively easily diagnosed. Gluten proteins elicit an aggressive immune response in the gut, and a gluten free diet is the therapy of choice. Wheat allergy is often more difficult to diagnose, but usually recognized by an immediate reaction to wheat consumption. Here gluten and non-gluten proteins are the trigger.”
“The main problem with NCWS was that the trigger as well as the clinical manifestations remained in the dark, until recently in my lab at Harvard Medical School in Boston we were able to identify the ATIs in wheat as mild inflammatory immune activators in the intestine,” Schuppan explained. “Since then, it is has become highly likely that this family of proteins is the cause of symptoms of NCWS,” confirmed PD Dr. Friedrich Longin, scientific head of the Wheat Unit at the University of Hohenheim and co-initiator of the joint research project on “Wheat intolerance: influence of wheat varieties and growing conditions on innate immune reactions,” funded by the German Research Foundation (DFG). ATIs are proteins that are naturally present in wheat. Just how many proteins of the ATI family and to what extent their content and composition are determined by the wheat variety and environmental growing conditions are not known, although researchers have first data that these factors can vary widely with wheat variety.