Wheat bran is the outermost shell of the wheat grain. It is formed from the walls of the fertilized wheat flower's ovary. Wheat bran is notable for containing large amounts of fiber, which is useful for alleviating certain gastrointestinal issues while exacerbating others.
Bran is nutrient-rich, which is why it is both added to and removed from many grain-based foods. The fatty acids in bran are essential to human health, but they are liable to go rancid, reducing the overall shelf life of whole grains. Bran's high fiber content can cause flatulence and stomach discomfort, despite also helping move food through the gastrointestinal tract to alleviate constipation. Wheat bran in particular contains a relatively large amount of protein for a non-animal-based food, making it useful for those on a meatless diet.