Dietary fibers are long-chain carbohydrates (polysaccharides) that are indigestible by the human digestive tract. The value of dietary fiber is that it provides bulk to the bolus moving through the digestive tract. There are two great advantages to this: by bulking up the bolus, eventually the stool, it's easier for the digestive system to move it through, and the bulkier stool also tends to retain moisture to make it easier to eliminate with less straining and abrasion.
There are two principal types of dietary fiber: soluble and insoluble. Insoluble fiber is simply bulk that changes little as it passes through the body. Soluble fiber, on the other hand, forms a soft gel in solution with water. Soluble fiber has been shown to be able to reduce blood cholesterol levels and slows the absorption of glucose from the intestine.
Soluble fiber is found in some fruits (particularly oranges, also apples and bananas), oats, legumes (peas, soybeans, and other beans), other vegetables, such as broccoli and carrots, and a grain called psyllium. Legumes also typically contain shorter-chain carbohydrates that are indigestible by the human digestive tract but which are digested by bacteria in the small intestine, which is a cause of flatulence.
External link
Database of Fiber-Containing Foods (http://www.highfiberdiet.net)
DietaryFibre, remains of plant cell walls; a complex mixture of carbohydrates that resist digestion in the intestinal tract and are therefore apparently of no value in the diet.
Fibre will bind a proportion of the bile salts (and cholesterol itself, which is also secreted in the bile), so that they are excreted in the faeces rather than being reabsorbed, thus causing more cholesterol to be used for bile salt synthesis.
Bile salts have also been implicated in the development of cancer of the large intestine—if they are bound to dietaryfibre rather than free in solution, they cannot interact with the intestinal wall in the same way to promote the development of tumours.
Feeds |
Contact