Gluten are a group of protein in cereals, especially in wheat. Wheat is closely related to other cereal grains, especially rye, barley, and oats, hence these grains also contain some gluten.

Gluten are the proteins in wheat that are responsible for the strong structure of a dough. The gluten proteins are responsible for the network that is formed in the process of making bread. This structure that forms during the raising period is very important, without gluten there will be no structure and the bread will not leaven.

Gluten are for most people a normal protein that is easily digested via the stomach-gut channel. However a small part of the population cannot digest gluten. These people are gluten intolerant, which is most commonly referred to as celiac disease.

Gluten is a mixture of a series of individual proteins classified in two groups, the Prolamines and the Glutelins. The main prolamine protein, Gliadin, seems to be the major problem in celiac disease or gluten intolerance; gliadin antibodies are commonly found in the immune complexes associated with this disease.

When people with celiac disease eat foods containing gluten, their immune system responds by damaging the small intestine. Specifically, tiny fingerlike protrusions, called villi, on the lining of the small intestine are lost. Nutrients from food are absorbed into the bloodstream through these villi. Without villi, a person becomes malnourished--regardless of the quantity of food eaten.

Because the body's own immune system causes the damage, celiac disease is considered an autoimmune disorder. However, it is also classified as a disease of malabsorption because nutrients are not absorbed. Celiac disease is also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy.

Celiac disease is a genetic disease, meaning that it runs in families. Sometimes the disease is triggered--or becomes active for the first time--after surgery, pregnancy, childbirth, viral infection, or severe emotional stress.