Gut Microbiota In Vitro Fermenting Destarched Dietary Fiber To Produce SCFA

Dietary fiber was a necessary human nutrient, played an important role in nutrition and health care functions. After dietary fiber got into the intestine, it can be fermented partly or all by large intestine probiotic, resulting in a large number of short-chain fatty acids, lower intestinal pH to improve the breeding environment for intestinal flora. Short-chain fatty acids in human intestine include acetic acid, propionic acid, butyric acid, isobutyric acid and lactic acid, etc.This paper destarched wheat bran, potato resistant starch, pectin and Isomaltooligosaccharide were used respectively as the carbon source, using human excrement as a source of intestinal flora, to ferment different intestinal flora in vitro. Then fermented fluid would be obtained at different time and measured the changes in pH value and the type and quantity changes of short-chain fatty acids (SCFA). Main results are as follows:(1) pH trends:during the fermentation process of intestinal flora from different carbon sources of culture medium, an overall downward trend of the pH value of fermented fluid was found with prolonging fermentation time.(2) changes in short-chain fatty acids:while destarched wheat bran, potato resistant starch, pectin and Isomaltooligosaccharide were used respectively as the carbon source, it was found that all could be used by Bifidobacterium, Bacteroides, Enterobacteriaceae and lactic acid bacteria to produce SCFA which was beneficial to the body, but the production and types vary. The production of butyric acid was relatively low and some bacteria can't even ferment butyric acid. The production of Acetic acid was the largest among all SCFA. During the fermentation process the amounts of SCFA did not simply increase by time, i.e. the amounts of propionic acid and lactic acid became lesser at the end of fermentation of some flora.