Oats do not contain gluten but a similar protein to gluten called avenins. Current research and clinical studies suggest that pure oats are safe for the majority of people with coeliac disease and can be tolerated without signs of intestinal inflammation. However a major concern is the contamination of oats with wheat, rye or barley and for that reason only certified gluten free oats should be included in a coeliac diet.
Coeliac UK suggests that 19 out of 20 people with coeliac disease can include uncontaminated gluten free oats with no ill effects, however there may be a very small number of people with coeliac disease who may be sensitive to the protein avenin that is found in oats. In these cases avenin may trigger an immunological response similar to the response produced by the gluten of wheat, rye or barley.
It is therefore important that pure gluten free oats are introduced gradually, so that symptoms can be monitored, and it is recommended that symptoms be monitored with coeliac serology by a health care practitioner to ensure suitability.