What are the types of dietary fiber?

There are two types of fiber: soluble and insoluble. Fiber in cell walls is insoluble in water. These include cellulose, hemicellulose, and lignin. Insoluble fiber binds water as it passes through the digestive tract, making stools softer and bulkier. It also stimulates peristalsis-the rhythmic contractions that move food along the digestive tract, preventing constipation and hemmorhoids. Insoluble fiber also prevents irritable bowel syndrome and diverticulosis, a painful inflammation of the diverticula, which are pouches of the intestinal wall. Because fiber accelerates the transit of carcinogens in the gastrointestinal tract, colon cells are exposed for a shorter time to these toxins, and the likelihood of colon cancer is reduced. Insoluble fiber also helps to prevent gallstones in women.

Soluble fiber, also called viscous fiber, is found inside plant cells. Pectin, gum, and beta-glucan are soluble fibers. Soluble fiber increases the viscosity of food, which slows the movement of food through the intestines, preventing diarrhea. Your body uses cholesterol to produce bile acids, some of which are excreted daily. Soluble fiber binds to bile acids, reducing the amount of bile reabsorbed in the intestines, and increasing the amount of bile that is excreted in the feces. To make up for this loss of bile, the liver makes more bile salts, using more cholesterol to make them. In order to obtain the cholesterol necessary to make more bile salts, the liver increases its production of low-density lipoprotein (LDL) receptors. These receptors pull cholesterol out of LDL molecules in the bloodstream. Therefore, the more bile salts the liver makes, the more LDL cholesterol is pulled from the blood. One of the short-chain fatty acids produced by the fermentation of soluble fiber in the large intestines may also inhibit the amount of cholesterol produced by the liver. A high-fiber diet reduces total cholesterol, triglycerides, and Very Low Density Lipoprotein-the most dangerous form of cholesterol. This prevents the buildup of plaque in the arteries and improves cardiovascular health. It also lowers the risk of Heart disease.