Fermentation Characteristic System Of Sparassis Crispa Polysaccharides And Its Effect On Intestinal Microecosystem In Mice

[Objective]To gain insights into valuable evidence for applications of Sparassis crispa polysaccharides(SCPs)as functional food materials in the industrial process,the fermentation system of SCPs and its effect on the intestinal microecology of mice were systematic investigated.[Methods](1)The human feces were used as the fermentation model to simulate the in vitro fermentation system of SCPs.The changes of p H value,total sugar content,reducing sugar content,monosaccharide and short-chain fatty acid content of fermentation products after fermentation of SCPs at different time points were measured,so as to explore the characteristics of the glycolysis of the polysaccharide in the intestinal tract.(2)96 clean grade KM mice(6 w,25 ±2 g)were randomly divided into three groups: blank group,low dose group,middle dose group and high dose group.The test group is respectively filled with a polysaccharide solution of 50,100,150 mg/ kg·bw·d,and the blank group was given 0.9% normal saline.After 1w,2w,3w and 4w,samples were collected to determine the water content of fresh feces,colon length,index and villus length of mice,short chain fatty acids,reducing sugar and monosaccharide of large intestine content.The composition and diversity of intestinal flora were analyzed by traditional culture method and high-throughput technique.The characteristics of glycolysis and its effect on intestinal microecosystem of hydrangea polysaccharide in animal intestines were investigated.[Results](1)The study of in vitro fermentation of SCPs showed that p H value decreased first and then increased,OD600 nm value first increased and then decreased,total sugar content decreased gradually,while reducing sugar content increased first and then decreased.The monosaccharide in the glycolysis product was composed of galactose,xylose,mannose,fructose and glucose,and the relative content of each monosaccharide increased and then decreased,in which glucose could not be detected 24 hours later,fructose utilization rate was more than 90%,mannose was not detected 48 hours later,xylose utilization rate was only 51.9%,the lowest utilization rate of xylose was 51.9%,and that of xylose was only 51.9%,and that of xylose was only 51.9%.However,the relative content of galactose began to decrease after 12 h fermentation,and the utilization rate was 86.2%;Short chain fatty acids are composed of hexanoic acid,pentanoic acid,propionic acid,butyric acid,heptanoic acid and adipic acid.Within 6 h,the content of hexanoic acid is the highest,the content of propionic acid is 28.15% of the total short chain fatty acid at 12 h,and the content of butyric acid is the most in total short chain at 24 h.The content of pentanoic acid was28.47% of total short chain fatty acid at 48 h.(2)The study of Fermentation of Sparassis Crispa polysaccharides and its effect on intestinal microecology in mice showed that The colon index,the length of the colon and the length of the villi were all increased,and the difference was significant or very significant(P <0.05 or P <0.01);the contents of short chain fatty acids in large intestine of mice were significantly increased(P < 0.01).The contents of acetic acid,butyric acid and valproic acid increased all the time,while propionic acid decreased after 2weeks,but still higher than that of control group.The contents of reducing sugar and monosaccharide were increased,and the contents of reducing sugar and monosaccharide were higher than those of control group;The difference was significant or extremely significant(P < 0.05 or P < 0.01).The total number of Lactobacillus and bifidobacterium colonies increased significantly(P < 0.01),and the total number of Escherichia coli colonies decreased significantly(P < 0.01).The results of 16 s R DNA high throughput sequencing showed that the abundance,diversity and structure of intestinal microflora in the experimental group were better than those in the control group,and the diversity of intestinal microflora in the high dose group was the best,and the ratio of mycorrhizal to thick-walled bacteria increased compared with the control group,and the relative abundance of Probiotics family,like Lachnospiraceae,Ruminococcaceae,Bacteroidales_S24-7_group,Porphyromonadaceae,Rikenellaceae,Prevotellaceae and Bacteroidaceae were significantly increased(P < 0.05),and the relative abundance of the harmful bacteria family such as Alcaligenace and Enterobacteriaceae were decreased significantly(P < 0.05).[Conclution] SCPs can be used as a substrate by intestinal microorganisms to produce a large number of short-chain fatty acids,its monosaccharide composition will affect SCFA production,these SCFA can continue to act on mice.At the same time,the polysaccharide of hydrangea can increase the abundance and diversity of intestinal flora,improve the structure of intestinal microflora,and have a positive effect on the intestinal microecosystem of mice.