In people with celiac disease, immune cells in the intestines known as T cells react to gluten, a protein in wheat, and its cousins in other grains. That means no wheat, rye, or barley. Oats, however, are still open for debate. A group of European researchers looked at oats in celiac disease.

What the researchers wanted to know: How do T cells in the intestines respond to oat proteins?

What they did: All nine of the patients in the study had been exposed to oats before. The researchers took a little biopsy of each patient's intestines and presented the intestine chunks with oat proteins that had been partly digested in the lab.

What they found: Some of the patients had immune reactions to oats. Their T cells reacted to at least two different oat proteins.

What the study means to you: People with celiac disease can't necessarily eat oats safely. People with celiac disease can hurt their intestines unwittingly, by eating the wrong foods, so even those who eat oats regularly could have complications later.

Caveats: The researchers don't know how often oats might cause complications; that would require long-term studies of patients who eat oats.

Find out more: An overview of celiac disease from the Mayo Clinic

A list of a surprisingly large number of grains and flours (artichoke flour, anyone?), and whether celiac disease patients can eat them

Read the article: Arentz-Hansen, H., et al. "The Molecular Basis for Oat Intolerance in Patients with Celiac Disease." PLoS Medicine. October 2004, Vol. 1, No. 1, e1.

Abstract online: http://medicine.plosjournals.org