Effect Of Soluble Dietary Fiber Of Sweet Potato On Intestinal Microflora

Soluble dietary fiber in sweet potato dregs was used as the main research object in this study.The composition of soluble dietary fiber in sweet potato dregs was analyzed.The effects of soluble dietary fiber from sweet potato dregs on the proliferation of intestinal probiotics and the changes of intestinal flora metabolites were evaluated by vitro culture and vitro fermentation.Animal experiments were carried out in order to find out the effects of soluble dietary fiber in sweet potato dregs on serum biochemical indexes and intestinal microbial diversity in mice.The soluble dietary fiber in sweet potato dregs was extracted with reference to GB 5009.88-2014.It testified that the soluble dietary fiber of sweet potato dregs mainly included neutral sugar?34.57%?and uronic acid?23.34%?.Among them,neutral sugars mainly include rhamnose,arabinose,xylose,glucose and galactose,and the percentage of each component is:8.16%,8.21%,7.03%,68.21%and8.37%.In vitro culture of bifidobacteria and lactobacillus plantae,soluble dietary fiber promoted the proliferation of both probiotics.At the 10th hour of culture,the number of both probiotics had reached the maximum.For lactobacillus,soluble dietary fiber from sweet potato dregs added at 10g/L had the best proliferation effect,while it had the best value-added effect for bifidobacterium at 2.5g/L.Both strains of probiotics can cause a decrease in pH during the growth process.The addition of 10g/L of soluble dietary fiber from sweet potato dregs can reach a pH value of 5.41,while the bifidobacterium can reach a minimum pH value of 4.93 at a concentration of 2.5g/L.During the experiment of in vitro fermentation and culture,SDF can affect the metabolites of intestinal flora:the addition of soluble dietary fiber can reduce the content of pH and NH₃-N in the fermentation broth,increase the amount of gas produced in the fermentation broth,and the yield of short-chain fatty acids.In promoting the production of short-chain fatty acids,the addition of soluble dietary fiber had the most significant effect on acetic acid?the yield increase rate of SDF10g/L group was 335%compared with the blank group?.Animal experiments were conducted to study the effect of soluble dietary fiber on intestinal flora.It was found that soluble dietary fiber from sweet potato could increase the content of low-density lipoprotein cholesterol?LDL-C?,immunoglobulin G?IgG?and reduce the content of total cholesterol?TC?in serum of mice.The addition of soluble dietary fiber from sweet potato dregs could improve the amount of OTU in the intestinal tract of mice and the richness of bacterial community.There were significant differences among the groups in phylum,order and species,indicating that the addition of soluble dietary fiber from sweet potato dregs could play a role in regulating intestinal flora.It also helps to increase the content of lactobacillus,reduce the content of harmful bacteria such as desulfurization vibrio,Aerococcus and Enterococcus,and reduce the proportion of Firmicutes and Bacteroidetes.