Study On The Effect Of Wheat Bran Oligosaccharides On Intestinal Flora

China is a large wheat planting country,the output of wheat reached 133.59 million tons in 2019.As the main by-product of wheat processing,the output of bran accounts for about one-fifth of the wheat processing,which is a rich resource that can be used.The structure of wheat bran contains a variety of active groups,which have biological activities such as lowering blood lipids and blood sugar,regulating intestinal flora,anti-caries and anti-tumor.This paper to study the effects of wheat bran oligosaccharides on the intestinal flora and bodyrelated immunity by animal experiments to improve the utilization value of wheat bran and promote human health.In this paper,wheat bran pentosan was extracted from wheat bran by enzymatic hydrolysis firstly,and the sugar components were separated and purified by ethanol distribution precipitation method to obtain wheat bran oligosaccharides.The composition of the wheat bran oligosaccharides was determined by HPLC.Then,the in vitro culture experiment of wheat bran oligosaccharides was carried out in the in vitro fermentation medium containing the fecal microbial flora of healthy adults.In order to explore the influence of wheat bran oligosaccharides on the intestinal flora and related immunity of the body,animal experiments were carried out on weaned mice in different environments,and the secondgeneration high-throughput sequencing method was used to analyze the bacteria in mouse stool samples.The main methods and results are as follows:The wheat bran pentosan is extracted by enzymatic method,and the wheat bran oligosaccharide is obtained by separation and purification by ethanol distribution precipitation method.Determining the xylose content in wheat bran by HPLC,oligosaccharides was content 4.1%,xylobiose was content 34.2%,and xylotriose content was content 12.7%.After acid hydrolysis,monosaccharides are obtained.The monosaccharides are mainly composed of xylose and arabinose,and the ratio of xylose,arabinose and glucose is 3.5:1:0.7.The average degree of polymerization of wheat bran oligosaccharides is 2.3,and the average degree of substitution of arabinose is 0.29.In the experiment to study the effect of AXOS on the intestinal flora of naturally temperature-controlled mice,48 three-week-old male mice under weaning stress were randomly divided into four groups A,B,C,and D.They were kept in the animal room.The mice in group A were fed with wheat bran oligosaccharides(AXOS).Group B was fed with commercial xylo-oligosaccharides(XOS),group C was fed with wheat bran oligosaccharides+ ferulic acid(addition of 0.03% ferulic acid)(AXOS+FA),group D(CTR)was fed with saline The stomach served as a control group.The feeding dose was 0.23 g/(Kg·BW),the feeding amount was 0.2 m L,and the feeding was continuous for 21 days.The mouse feces were collected and sequenced by the second-generation high-throughput method based on 16 S r RNA V4-V5.The results showed that the intestinal flora of mice was mainly Bacteroidetes,Firmicutes and Proteobacteria at the phylum level,and their abundances were 45-55%,30-50%,and 10-30%,respectively.The four groups have no significant differences in the richness of the three communities;the dominant flora of the mouse intestinal flora at the genus level are: Faecalibaculum,Bacteroides,Akkermansia,Parasutterella,Ruminiclostridium,Mucispirillum,Anaerotruncus,Intestinimonas,Lactobacillus,Oscillibacter.AXOS can significantly reduce the abundance of Faecalibaculum,and significantly increase the abundance of Intestinimonas,Oscillibacter,Alitipes,Coprococcus,and Bifidobacterium.In the experiment to study the effect of AXOS on the intestinal flora of mice in a sterile feeding system,48 three-week-old male mice under weaning stress were randomly divided into four groups: A,B,C and D.Group A was fed with a medium dose(0.23 g/(kg ·BW))of AXOS,and group B was fed with a medium dosage(0.23 g/(kg ·BW))of XOS.group C was fed with high-dose(0.70 g/(kg ·BW))of AXOS,control group D(CTR)was fed with normal saline,all mice in the group were fed 0.2 m L,feeding continuously for 21 days.After feeding,mouse feces were collected and dissected.And sequenced by the second-generation highthroughput method based on 16 S r RNA V3-V4.The results showed that AXOS can promote the growth of mice during the growth period of the mice;the spleen index of the two groups of wheat bran oligosaccharide group mice were higher than that of the blank group,and the liver index was lower than that of the blank group,while the high-dose AXOS can improve mouse thymus index;both groups of AXOS have an effect on short-chain fatty acids in mouse feces.Medium and high doses of AXOS can reduce the content of lactic acid in mouse feces,increase acetic acid,propionic acid,Butyric acid content;Medium and high doses of AXOS can significantly increase the s Ig A content in mouse colon tissues,and AXOS can protect the intestinal mucosa and improve immunity;For the structure of intestinal flora,Bacteroidetes,Firmicutes,Proteobacteria and Verrucomicrobia are the main communities at the phylum level distribution.The two groups of AXOS have no significant effect on the abundance of Bacteroidetes and Firmicutes,while high-dose AXOS can increase the abundance of Proteobacteria,and both groups of AXOS can reduce the abundance of Verrucomicrobia;the distribution structure of intestinal flora at the genus level is as follows: The top ten species are Prevotella,Oscillospira,Akkermansia,Sutterella,Bacteroides,Ruminococcus,Desulfovibrio,Lactobacillus,Mucispirillum,Helicobacter.Both groups of AXOS can significantly reduce the abundance of Akkermansia and Lactobacillus,and significantly increase the abundance of Sutterella and Helicobacter.The results showed that AXOS could increase the abundance and diversity of the intestinal flora of mice under weaning stress,and promote growth during the growth of mice and had a positive impact on the immune system.