An estimated 1 in 7 people in the US are allergic to gluten, which is a protein found in wheat, barley, and rye. Gluten intolerance, if untreated, can lead to celiac disease, causing inflammation and damage to the small intestine and affecting nutrient absorption. It is important to recognize symptoms and seek testing, as treatments for both gluten intolerance and celiac disease involve eliminating gluten from the diet.