Gluten is a protein that is found in grains including wheat, rye and barley. A less-common grain called triticale, which is a cross between wheat and rye, also contains gluten. Any processed foods that contain ingredients such as white flour, whole wheat flour, wheat germ, semolina or graham flour also contain gluten.
There are a number of foods that people don't expect to contain gluten but often do. These include commercially prepared broths, salad dressings, soy sauce, seasoned rice mixtures, matzo balls and some hot dogs. Wheat products are added during the manufacture of these products, and as a result, they contain small amounts of gluten. In order to determine whether a packaged food item contains gluten, look closely at the ingredient list. Products labeled "wheat-free" may not necessarily be gluten-free because they may be made with rye or barley, which also contain gluten.
Gluten is a plant protein that most people have no trouble digesting. However, in people who are gluten-intolerant or suffer from celiac disease, gluten causes inflammation in the small intestine. Following a gluten-free diet is the only way for these people to eliminate their symptoms, which may include chronic diarrhea, vomiting, weight loss, fatigue and delayed growth.