Fiber acts as a bulking agent in the stomach and intestine, which means you feel fuller and may eat less. Soluble fiber attracts water and forms a gel-like substance as it passes through the digestive tract. This slows digestion and lowers the rate of nutrient absorption, helping to maintain glucose and cholesterol levels that are already within the normal range.
Insoluble fiber acts as a natural laxative that speeds the passage of foods through the stomach. When the non-digestible fibers reach the colon, anaerobic bacteria degrade them through fermentation. This process produces byproducts known as short-chain fatty acids, which help maintain proper acid/base balance in the colon and may be beneficial to healthy colonic mucosa