Gluten free foodstuffs can be helpful to people suffering from Coeliac disease, which is an auto-immune disease, where the body's immune system attacks its own tissues. The attacks are triggered by eating gluten (a protein found in wheat, rye and barley cereals, sometimes oats too) and can damage the lining of the small intestine (the gut). So, a gluten free diet means that the gut gets a chance to heal and the symptoms of the disease to dissipate (nausea, bloating, diarrhoea etc etc).