In its pure form, oatmeal can be part of a gluten-free diet, but most commercial oatmeal manufacturers also process their oats with wheat, barley and rye, making such products unsafe for gluten-free diets. Bob's Red Mill Gluten-Free oatmeal processes in a gluten-free facility, making it safe for gluten-free diets.
Other brands that make 100 percent gluten-free oatmeal include GF Harvest, Glutenfreeda Foods, Holly's Oatmeal and Montana Gluten-Free. While most people with celiac disease can process oatmeal, a select few who have an allergy to avenin cannot, states About.com. Out of the small percentage of people who have celiac disease, only about 10 to 15 percent of them also have an allergy to avenin.