Oat bran is the outer layer of the oat grain. It packs more fiber than rolled or ground oats. Most of that fiber is beta-glucan, a soluble fiber that forms a gel once it hits the gut.
The gel slows how quickly the body absorbs carbs and binds to bile acids that contain cholesterol. This helps maintain cholesterol levels already in a normal range and supports steady blood sugar after meals. The fiber also adds bulk to stool, which encourages regularity.
People stir oat bran into hot cereal, yogurt, or smoothies and often bake with it. Powders and capsules are available too. Take it alongside meals to feel the effects and make it easier on the stomach.
Start small and increase slowly so the extra fiber does not cause bloating or gas. The fiber can interfere with the absorption of some medications. Keep oat bran and any drugs separated by at least two hours.