Avenin is a protein found in oats. It is analogous to the proteins (gliadin) involved in Coeliac disease.
Studies of tolerance of avenin by Coeliac patients are inconclusive. Oats are generally considered safe, if certified gluten-free, but some studies have shown avenin to induce immune responses similar to those elicited by gluten proteins. Coeliac and gluten-sensitive individuals should be aware of these inconsistencies and test their own tolerance to oats.
Different cultivars of oats have variations on avenin proteins, which have been shown to elicit different levels of immune response.
Oats, oat products
Scandinavian Journal of Gastroenterology
Scandinavian Journal of Gastroenterology 2
The American Journal of Clinical Nutrition
Journal of Cereal Science