Dietary insoluble fiber

Dietary insoluble fiber is a complex carbohydrate found mostly in plant cell walls, composed of cellulose, hemicellulose, and lignin. It does not dissolve in water and remains largely undigested as it passes through the gastrointestinal tract. Its primary health effects are mechanical: it adds bulk to stool, promotes intestinal motility, and helps prevent constipation. Insoluble fiber is found in foods such as whole grain wheat products, wheat bran, brown rice, nuts, seeds, and many vegetables and fruits, particularly those with edible skins. It is not a receptor, enzyme, or molecular entity and does not act as a direct therapeutic target, but is considered a critical dietary component for supporting digestive health, regularity, and potentially reducing risk of certain metabolic and gastrointestinal diseases. Insoluble fiber may also influence the gut microbiota, although far less is fermented than soluble fiber[1][3][4][6][9].

Other names

Insoluble fiberWater-insoluble fiberRoughage (colloquial)Bulk (colloquial)