Oat bran

Bran, also known as miller's bran, is the hard outer layers of cereal grain. It consists of the combined aleurone and pericarp. Corn bran also includes the pedicel . Along with germ, it is an integral part of whole grains, and is often produced as a byproduct of milling in the production of refined grains.

Bran is present in cereal grain, including rice, corn (maize), wheat, oats, barley, rye and millet. Bran is not the same as chaff, which is a coarser scaly material surrounding the grain but not forming part of the grain itself, and which is indigestible by humans.