GlutN

As the third most large crop production, wheat has a huge economic importance. It is also a major contributor to the human diet providing about 20% of the total energy and 22% of the total protein. Wheat-based food consists of various processed products. Processing is possible thanks to the viscoelastic properties of the dough due to the gluten network, which is formed by storage proteins (glutenin and gliadin) mixed with water. While gluten is necessary for processing, it also triggers gluten-related disorders, which encompass allergy, coeliac disease and non-coeliac gluten sensitivity (NCGS). NCGS is badly characterized and difficult to objectively diagnose, as no clinical biomarker is available. Over the past decade, NCGS is more and more self-diagnosed, which makes the gluten-free diet more frequent, without objective clinical criteria. Thus, it opens a societal debate on the relevance of gluten-free diets for people without coeliac disease or wheat allergy. In addition, gluten avoidance hardly impacts the wheat sector. In this context, the GlutN project aims at deciphering some mechanisms able to cause NCGS, postulating its prevalence, and identifying clinical biomarkers to facilitate its diagnosis. As bread is the main form of gluten ingestion, GlutN will propose processes to bake specific breads adapted to NCGS patients. The underlying hypothesis is that NCGS may be triggered by strong interactions between protein and starch making a gluten-starch complex, which could be resistant to digestion. Thus, starch and storage protein, being the major components of wheat grain, will both be considered, as they constitute in bread a compact matrix with starch granules entrapped in a protein network. To reach the objectives, GlutN is based on an translational multidisciplinary approach from plants to patients. Besides the management task, GlutN is structured in six operative tasks. First, gluten-free consumers will be profiled in an overall approach (sociodemographic, dietary patterns, health status and motives) thanks to an epidemiological study. Then, tasks 2 to 4 will help to relate the structuration of the gluten/starch matrix in bread to document: - the diversity of gluten/starch-related genes, gluten composition and starch features, which will be analyzed in a set of 75 lines comprising old and modern cultivars (Task 2). Based on their genotypic and phenotypic data, 10 lines will be selected. - the baking processes (Task 3). The 10 lines will be transformed using three different baking processes. For each bread, the structure of the gluten/starch complex will be analyzed by microscopy and NMR technics. Breads will be evaluated by sensory analysis to identify those having a better hedonic value and those expected to be selected for commercial development. Five kinds of breads with different structure of the gluten/starch matrix will be selected. - the in-vitro digestibility from the mouth (mastication) to the gut (Task 4) of the five breads. The two most digestible breads will be selected. Task 5 is a clinical trial on NCGS patients (diagnosis based on history, clinical symptoms and clinical response to a gluten-free diet).They will be included in a randomized double-blind cross over study with periods of diet containing or not gluten. Biological samples will be analyzed by metabolomics to identify specific biomarkers. Finally, NCGS patients will be submitted to two “new” breads to evaluate their clinical and biological tolerance. As gluten became a societal issue, Task 6 will be dedicated to communication and dissemination. The results of the project will be disseminated to the cereal, bakery and health sectors as well as the general population by press release. In conclusion, GlutN is expected to have fundamental insights (NCGS basis), economic (NCGS clinical biomarkers for objectifying the diagnosis, specific wheat cultivars/breads), and societal insights (dissemination to help consumers and stakeholders).