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
Wheat allergy high molecular weight glutenin subunit, and similar proteins in other "Triticeae" genera, enter the blood stream during exercise where they cause acute asthmatic or allergic reaction. One recent study of ω-gliadins demonstrated these gliadins are more similar to the bulk of oat avenins than α/β or γ gliadins but, so far, oat avenins have not been linked to WDEIA. Wheat may specifically induce WDEIA and certain chronic urticaria because the anti-gliadin IgE detects ω-gliadins expressed by most of the Gli-B1 alleles, but prolamins extracted from rye or wheat/rye translocates invoke almost no responses. The Gli-B1 gene in wheat, "Triticum aestivum",