Whole, unprocessed oats do not contain gluten, although oats can be cross-contaminated with gluten-containing particles during the manufacturing process. Although oats do not contain gluten, which is a protein found in barley, rye, triticale and wheat, they do contain a similar minor protein called avenin.
People with avenin-related sensitivity may experience an allergic reaction to oats. As of 2014, there is still much controversy regarding the gluten-free status of oats; however, the University of Chicago notes that uncontaminated oats are a "safe" food for those who suffer from gluten allergies. Several manufacturers, including Bob's Red Mill, Cream Hill Estates and GF Harvest, offer uncontaminated oat products, including oat flour and oatmeal.