The milling process gently separates the protective outer layer of the wheat berry from the endosperm and oil-rich germ. The resulting wheat bran boasts a high fiber content (6 grams per 1/4 cup serving) that also acts as a prebiotic, which may promote healthy gut bacteria and increasing diet transit time, thus guarding against constipation. Some studies indicate that wheat bran fiber may also slow fermentation in the gut, allowing short chain fatty acids to move throughout the colon.