A gluten-free diet is indicated for people who suffer from Celiac Disease. They have to eliminate gluten from their diet. Gluten is a protein in many grains and it’s why these people have to avoid wheat, rye, barley, etc. On the Low FODMAP diet, wheat, barley, and rye also have to be eliminated, but due to their fructan (a type of carbohydrate) content, not gluten. Furthermore, the Low FODMAP diet also limits the consumption of other types of carbohydrates (lactose, polyols, etc.) that are not limited in the gluten-free diet.