What's Gluten?Gluten (say: gloo-tin) is a protein found in wheat, rye, and barley — grains that are in many everyday foods. Most of us eat food with gluten with no trouble. But for some people, eating gluten can cause a reaction in their bodies. Someone who has this problem has celiac (say: see-lee-ak) disease.
After you eat food, it goes to your stomach, which is part of a group of organs that make up your digestive system. An important part of the digestive system is the small intestine, which is lined with villi (say: vil-eye).
Villi are usually described as microscopic, finger-like projections. Weird, huh? Fingers in your intestines! But don't forget that they're microscopic, meaning they are extremely small — so small you can't see them without a microscope. The villi are important because they absorb nutrients into the body.
For someone with celiac disease, eating gluten — in a piece of bread, for instance — causes an immune system reaction. Your immune system ordinarily keeps you from getting sick, but in someone with celiac disease, the body starts damaging and destroying the villi. Without villi, the body can't absorb vitamins and nutrients from food. Without enough nutrients, a kid's body has a tough time staying healthy and growing properly. Even if the person eats a lot, he or she still might lose weight and might develop anemia (say: uh-nee-me-uh) from not absorbing enough iron.