Wheat flour is the only flour with gluten of sufficient quantity and quality for making regular yeast breads. Some other grains, primarily rye and spelt, also contain gluten proteins, a fact important to people with gluten sensitivity or celiac disease. Nevertheless, the proteins do not form a good, elastic gluten useful for bread making. With the exception of a few specialty baked goods, these other flours and meals are mixed with wheat flour for most baking purposes.