Medical experts agree that non-celiac gluten sensitivity is a condition, but they don't know a lot about it, such as long-term effects or even whether it's just one illness. Dr. Stefano Guandalini of the University of Chicago's Celiac Disease Center said some people who do not have celiac disease do get a health boost from adhering to a gluten-free diet, but he does not know how many people may be gluten sensitive and there is no blood test that can aid in the diagnosis.