Abstract: Short-chain fatty acids (SCFAs) can be generated from a variety of dietary fibers through in vivo fermentation by intestinal microflora and are beneficial to human health. Three types of insoluble dietary fibers were selected from pectin, resistant starch, fructo-oligosaccharide and cellulose, mixed in a certain proportion and added to the rat diet. After six weeks of feeding, the rats were anatomized to collect intestinal contents, and the types and amounts of SCFAs in the intestinal contents were measured by GC to determine the optimal combination of SCFA types. The optimal combination of insoluble dietary fibers in the diet of female rats was pectin, resistant starch and cellulose with an amount of 2% for each of them. For male rats, the optimal combination was pectin, fructo-oligosaccharide and cellulose, each of which was added at 2%.

Key words: insoluble compound dietary fiber, short-chain fatty acids, in vivo fermentation, intestinal microflora