Coeliac disease disease genotypes. It is suspected that some of them may have been beneficial by providing protection against bacterial infections. The majority of the proteins in food responsible for the immune reaction in coeliac disease are the prolamins. These are storage proteins rich in proline ("prol-") and glutamine ("-amin") that dissolve in alcohols and are resistant to proteases and peptidases of the gut. Prolamins are found in cereal grains with different grains having different but related prolamins: wheat (gliadin), barley (hordein), rye (secalin) and oats (avenin). One region of α-gliadin stimulates membrane cells, enterocytes, of the intestine to allow larger molecules
Anti-gliadin antibodies This antibody is a recommended testing protocol in a proposed revision of the Codex Alimentarius. The new standards came about in part because of new sensitive and specific testing procedures. These procedures are capable of detecting wheat or multiple cereals at concentrations as low as 1 part per million (PPM or 1 mg/kg). A new barley-sensitive ELISA called the R5 sandwich assay does not detect gluten in any of 25 pure oat varieties, but it does detect barley, wheat and rye. Anti-gliadin antibodies Anti-gliadin antibodies are produced in response to gliadin, a prolamin found in wheat. In bread wheat it