Good Summary of Oat Consumption and Coeliac Disease

[Russ H]

It is complex and nuanced, but I think it is fair to say that for most people in remission from coeliac disease it is safe to consume 75 g (3 oz) of gluten-free oats per day.

https://www.frontiersin.org/articles/10.3389/fped.2019.00384/full

[Scott Adams]

The only caveat would be the ~9% of celiacs who can't tolerate avenin protein, which seems to be a related intolerance for a sub-group of celiacs.

[Russ H]

Yes. According to this study, in most people a reaction to oats is secondary to the reaction to gluten. When gluten is withdrawn from the diet and the immune response to gluten dies down, so does the one to oats. So it seems reasonable to wait until the antibody count has come down and the gut is healed before trying oats.

https://www.tandfonline.com/doi/abs/10.1080/00365520701832822?journalCode=igas20

However, a proportion of people with coeliac disease make a direct immune response to avenin, similar to to the one made against gliadin.