Research takes a step towards safe wheat for coeliacs

A study analysing the toxic components of proteins in wheat could be the first step towards developing wheat-based products that are safe for coeliacs.

Currently, the only treatment for coeliac disease is a strict gluten-free diet for life. Recent research has sought to understand the relationship between the proteins of wheat gluten and the reaction it produces in coeliacs. One hypothesis was that modern wheat production practices that aim to improve the viscoelasticity of bread dough have contributed to increasing the prevalence of coeliac disease since the late 20th century.

However, a new study published in the journal Food Chemistry demonstrates that even the oldest varieties of wheat, which have not been subject to alteration, can present toxicity through some components of gluten, called epitopes, that are responsible for the autoimmune response in coeliac patients.

The scientists analysed various kinds of wheat from several countries in order to assess what relationship there was between various kinds of wheat and their toxicity. They focused on some of the proteins in gluten, gliadins. The other proteins in gluten, glutenins, are the main causes of the strength of the mass of flour and what lend it its viscoelasticity.

“Out of the proteins in gluten, gliadins have the greatest clinical effect against the innate and adaptive immune responses that lead to coeliac disease,” said Marta Rodríguez-Quijano, a researcher at the Technical University of Madrid and one of the authors of the study, who explained there are various kinds of gliadins in every variety of wheat.

The scientists assessed the presence of T-lymphocytes — a type of cell in the immune system — related to coeliac disease in the various kinds of wheat.

“The results show that the different varieties of wheat produce considerably different immune responses depending on the T-cells analysed. Some varieties of this grain, such as the French ‘Pernel’ T. aestivum ssp. vulgare L., have low toxic epitope content,” explained Rodríguez-Quijano.

Towards safe products for coeliacs

The research reveals the potential of production practices to develop wheat products that are safe for coeliacs. “Genetic diversity makes it difficult to obtain a variety of wheat with no toxicity while maintaining the viscoelastic properties of gluten. For this reason, learning about the different varieties would enable production techniques to be developed to achieve this,” Rodríguez-Quijano said.

The project is a first step towards technologies based, for example, on selective modification of the glutamine residue present in the toxic components. In coeliac disease, identifying the quantity and distribution of toxic epitopes is the key.

“We hope this study enables products to be developed that are safe for coeliacs, with detoxification processes that combat the poor nutritional and technological characteristics of gluten-free products and thereby contribute to improving patients’ quality of life,” concluded Rodríguez-Quijano.