Gluten is a protein found in wheat, rye and barley. The specific names of the proteins are: (gliadin), (triticum) wheat, (secalin) in rye, and (hordein) in barley. Gluten is found in breads, baked products, cereals, pastas, soups, sauces. Gluten is a protein which is the glue that holds many products together, that is why it is used so often in baking and as filler in so many products, it is also used as filler in many products as well as cosmetics.

It is important to read labels carefully to avoid hidden gluten. Often even after reading a label you have to call a manufacturer to check if a product is gluten free since many things can be misleading.