Single amino acids and small chains of amino acids do not cause problems for the intestine nor would they be expected to cause problems with the immune system because lymphocytes are looking for longer chains. It appears, however, that gliadin is not completely broken up by intestinal enzymes. Several longer chains of amino acids remain intact.
Somehow, these larger chains enter the cells lining the intestine, and one of them attaches to an enzyme inside the cells. In people with celiac disease, the complex of the chain of amino acids and enzyme sets off an immune reaction that attacks the complex and, at the same time, damages the intestinal cells.
In the case of Amy—and others with celiac disease—the immune reaction starts when partially digested gluten goes from Amy’s intestine to her bloodstream. There, the epitopes trigger a series of reactions that lead to the release of small molecules called cytokines. Cytokines cause the cells lining the intestine to have increased blood flow—a condition known as inflammation.
Normally, inflammation is a good thing because the increased blood flow allows faster delivery of materials for destruction of the invading bacteria and a means for their quick removal. The problem is that inflammation of the intestinal lining does not stop as Amy continues to eat foods containing gluten. If inflammation goes on for weeks and months, Amy’s intestinal cells become damaged. As a result, she suffers from abdominal pain, diarrhea, and skin rashes.
Longer term exposure over years can result in intestinal damage. The damage can be so severe that her intestinal lining can no longer absorb nutrients. The most effective solution for anyone with gluten sensitivity is to avoid gluten completely. But that’s not easy. Sticking to a gluten-free diet is a challenge, especially because modern foods are heavily based on wheat. From baked goods to frozen pizza dough to boxed cereals and packaged noodles, products containing wheat flour can be found in nearly every aisle of our grocery stores.