Oats are naturally gluten-free, but they are often processed in factories that handle wheat, barley, or rye, too. This leads to cross-contamination and can trigger severe immune responses in people who have celiac disease. Even a small amount of gluten can damage the intestinal lining of a person with celiac disease. This can lead to nutrient malabsorption, stomach pain, and long-term health issues. So, people with celiac disease can have oats only if they are certified gluten-free and processed in separate facilities. However, even then, some may react to a protein in oats called avenin, which mimics gluten’s effects in rare cases.
