Gluten is the term for the storage protein of wheat. Wheat is approximately 10 to 15 percent protein; the remainder is starch. Gluten is what remains after the starch granules are washed from wheat flour. The gluten fraction that is most studied in celiac disease is gliadin, but there are other proteins that chemically resemble glianin in rye (secalins) and barley (hordeins). These proteins are not strictly glutens, but are generally include in the term and are toxic to people with celiac dies. Most of the studies in celiac disease look at gliadin, but it is possible that there are many other proteins in gluten to which people are sensitive.
If you look at the grain table, you will see that the grass family has numerous branches. Wheat, rye and barley – which contain gliadin, secalin, and harden proteins respectively – are closely related genetically. they come from similar drives that also include spelt, gamut, and triticale. Oats are on a different branch, closely related to rice and are believed to be safe for most people with celiac disease so long as they are not contaminated with wheat. Rice, corn, millet, sorghum, and several other grains are also same.
Normally when we digest protein, it get broken down in the stomach and small intestine into single amino acids or dipeptides (two amino acid molecules) that are readily absorbed by the small intestine. But the gluten molecule is resistant to the enzymes that break down proteins (peptidases). It is simply not digested well by humans. As a result, we are left with a long peptide chain, composed of thirty-three amino acids, that is called the toxic fraction of gliadin. This toxic fragment gets into the lining f the intestine, underneath the epithelial cells lining the villi. And some people develop an immunological reaction to this gliadin fraction that starts to inflame and destroy the villi.
It is unclear how the gliadin fraction gets into the muscle wall, but it may be related to breaks in the mucosal barrier caused by an infection. It is also unclear how gliadin initiates the immune response and intestinal changes that lead to celiac disease. This areas are the subject of current research into the disease. What is understood is that the gliadin fraction is the main environmental trigger and culprit is the disease. Essentially, celiac disease is an abnormal reaction to a normal food substance.
So while wheat may be the ‘staff of life’ for some, for others it more closely resembles that ‘terminator”.