Celiac disease is a disease of the small intestine. Food empties from the stomach into the small intestine where it is digested and absorbed into the body. While food is being digested and absorbed, it is transported by the small intestine to the colon. What enters the colon is primarily undigested food. In celiac disease, there is an immunological (allergic) reaction within the inner lining of the small intestine to proteins (gluten) that are present in wheat, rye, barley and, to a lesser extent, in oats. The immunological reaction causes inflammation that destroys the lining of the small intestine. This reduces the absorption of the dietary nutrients and can lead to symptoms and signs of nutritional, vitamin, and mineral deficiencies.
The destruction of the inner lining of the small intestine in celiac disease is caused by an immunological (allergic) reaction to gluten in the diet that inflames and destroys the inner lining of the small intestine. There is evidence that this reaction is partially genetic and partially inherited.
Gluten is a family of proteins present in wheat. Some of the proteins that make up gluten (the ones that are dissolved by alcohol) are called gliadin. It is the gliadin in gluten that causes the immunological reaction in celiac disease.
Barley and rye contain gliadin-like proteins and can cause celiac disease in genetically-predisposed individuals. Oats also contain gliadin-like proteins, but unlike barley and rye, the gliadin-like proteins in oats cause only a mild inflammation and that too in only a few individuals who are predisposed to develop celiac disease. Rice and corn do not cause celiac disease because they do not contain gliadin-like proteins.
The signs and symptoms of celiac disease vary depending on the degree of malabsorption, and ranges from no symptoms, few or mild signs and symptoms, to severe signs and symptoms. There are two categories of signs and symptoms:
- malnutrition including vitamin and mineral deficiencies
There is no cure for celiac disease. The treatment of celiac disease is a gluten free diet. Patients with celiac disease vary in their tolerance to gluten; some patients can ingest small amounts of gluten without developing symptoms while others experience massive diarrhea with only minute amounts of gluten. The standard treatment calls for complete avoidance of gluten for life.