Pure oats do not contain gluten. Oatmeal may contain gluten, because oats often are processed in facilities with machines that also process wheat, barley and rye. People with celiac disease and gluten sensitivity should only eat oats that have been certified as being gluten-free.
Oats that are gluten-free should be prepared and eaten with pans, bowls and utensils that are only used for preparing gluten-free foods. Gluten is a protein that is found in certain grains. People who are intolerant to gluten have a reaction in the small intestine that can result in stomach pains and problems absorbing certain nutrients.