A research project led by the Institute for Research in Nutrition and Food Safety (INSA) and the Faculty of Pharmacy and Food Sciences at the University of Barcelona, together with the Molecular Biology Institute of Barcelona (IBMB) of the CSIC (which stands for Consejo Superior de Investigaciones Científicas), has successfully designed and tested a gluten-degrading molecule that is a promising ally in the management of coeliac disease, an autoimmune disease whose symptoms are triggered by the consumption of gluten and other prolamins found in cereals. At present, there is a complete lack of treatment options beyond a diet free from gluten, which is difficult to maintain in Western societies where diets rely heavily on wheat products.
The major breakthrough is that the molecule is effective at very low concentrations and at a pH of 2 - the pH of the stomach - a condition that none of the molecules currently available or under development had previously achieved with efficiency. Although some of them are marketed as nutritional supplements, they are not an effective alternative to gluten-free diets.
The study has been published in the journal EMBO Molecular Medicine ahead of the International Day of Coeliac Disease - which takes place on 16 May - and is led by researchers Francisco J. Pérez-Cano (INSA-UB), and F. Xavier Gomis-Rüth (IBMB-CSIC). The co-first authors are Marina Girbal-González and Arturo Rodríguez-Banqueri (INSA-UB and IBMB-CSIC, respectively). Teams from the Institute for Food Science Research (CSIC-UAM), the University of Salzburg (Austria) and the Technical University of Munich (Germany) have also participated.
Counteracting the 'trigger' of coeliac disease
The trigger for coeliac disease are the prolamins, proteins found in most common cereals in our diet, such as wheat gluten. When these are digested in the stomach, they break down into smaller fragments (peptides). Some of these can be toxic, such as the gluten immunogenic peptides (GIPs), which can withstand the stomach's gastric acids and reach the small intestine. Among these, one of the most immunogenic is the the '33-mer', a fragment of the α-gliadin in wheat gluten that is highly immunogenic.
This poses a problem for people with coeliac disease, because once in the small intestine, the 33-mer and other GIPs bind particularly easily to a receptor of the immune system (the human leukocyte antigen, or HLA), triggering the inflammatory autoimmune response that causes the characteristic symptoms of the disease.
