People who have what is called Celiac disease, (a disease that causes damage to the small intestines if gluten is ingested) need to have gluten free foods in their diet.
About.com's Jane Anderson states in an article "Gluten-Sensitivity" that about 1 in every 133 American have are sensitive to gluten. Also, the symptoms are very common to other illnesses, which makes it very hard to diagnose.
To sum it up, check with your doctor and/or nutritionist before you start eating food products without gluten because in those who aren't gluten intolerant, GLUTEN is actually a necessary element and without it other complications may occur!
Research discovered at About.com, Wikipedia.com, Dictionary.com