Contrary to starch, fiber is not broken down well by our digestive enzymes. This is partly explained by the manner in which the monosaccharides are linked together. Whereas digestive enzymes (amylases) produced by people are very efficient in breaking the links between monosaccharides in starch, these enzymes are generally ineffective at breaking the links between monosaccharides in fiber. Plants build these bonds in a special way.
In the stomach, soluble fibers attract and bind to water and in turn form a gel-like material. This gel entraps food components such as sugars, cholesterol and fats and slowly carries them through the remaining
digestive tract. Insoluble fibers, on the other hand, tend not to contribute to the formation of gels. Because soluble fibers dissolve in water, psyllium husk, inulin, FOS and others are used in supplemental fiber drinks as discussed below and in Chapter 13.
As fiber reaches the colon, bacteria begin to breakdown (ferment) some of the fibers for energy and in the process produce gases such as carbon dioxide, methane gas, and hydrogen gas. These gases often lead to uncomfortable bloating and flatulence associated with higher fiber intakes. Soluble fibers are more fermentable than insoluble ones. In addition other molecules, such as short-chain fatty acids, are produced by bacteria, which can be absorbed into the body. These fatty acids yield a small amount of energy and health benefits. Therefore, foods or supplements providing psyllium, beta glucan (oats or barley), inulin, FOS, cellulose, guar gum, xanthan gum, and oligosaccharides will be
fermented and you can expect gas production.
Tidak ada komentar:
Posting Komentar