Jujube Polyphenols For The Improvement Of DSS-induced Ulcerative Colitis In Mice Based On Intestinal Microbiota Interactions

Ulcerative colitis(UC)is an inflammatory disease characterized by inflammation of the colon and rectal mucosa,but most of the therapeutic agents have side effects,and there is an urgent need to develop alternative therapeutic agents.Recent studies have found that the intestinal flora can alleviate the occurrence of UC by increasing the abundance and diversity of beneficial bacteria.The preliminary study of the research group found that Jujube polyphenols(JPE)can effectively improve the ulcerative colitis induced by sodium dextran sulfate(DSS).It is preliminarily inferred that there may be an interaction mechanism between polyphenol extracts and intestinal flora to alleviate ulcerative colitis,but the interaction mechanism is not clear.In this study,the potential effects of JPE on the microbial diversity and microbial metabolism of DSS-induced UC mice were investigated by 16S rRNA high-throughput sequencing.By constructing microbiota-depleted mice,the important role of intestinal microbiota interacting with JPE in improving UC was further verified.Elucidate its mitigating mechanism.The main research contents and results are as follows:(1)The mitigating effect of jujube polyphenol extract on UC mice through intestinal flora.The red jujube polyphenol extract obtained in the early stage of the research group was fed to UC mice,and the changes of intestinal microbiota of UC mice were detected by 16S rDNA sequencing technology.The diversity and abundance of intestinal flora were analyzed by comparing information with databases,combined with bioinformatics processing and statistical analysis.It was found that JPE could improve the a diversity and increase the abundance of beneficial bacteria in UC mice,proving that jujube polyphenol extract had an effect on UC Regulatory role of mouse intestinal flora.(2)Jujube polyphenol extract fermentation broth(JPE FB)induced DSS Mitigating effect of ulcerative colitis in depleted mice.The fermentation broth of jujube polyphenol extract obtained by the research group in the early stage and fecal fermentation was obtained,and a germ-free mouse model was established,and 200 mg/kg JPE FB was gavage,and the molding time was one week.Intestinal mucosal morphology is measured.The results showed that the DAI score of the mice with depleted colitis was reduced,the weight loss of mice was alleviated,and the diet of mice was reduced.At the same time,it also reduces the damaged integrity of the ileal wall of mice with depleted colitis and increases the number of goblet cells in colonic tissue.In summary,the interaction between JPE and intestinal flora has a certain alleviating effect on ulcerative colitis.(3)JPE FB alleviates DSS-induced microbiota depletion colitis in mice through NLRP3/oxidative stress pathway.RT-PCR was used to detect intestinal associated inflammatory factors in mice,and N LRP3 was detected by western blotting Inflammasome pathway-associated proteins(NLRP3,ASC,IL1β,GSDMD)and oxidative stress Changes in proteins(iNOS,MPO,COX-2).The results showed that JPE FB can downregulate inflammatory factors(IL-1β,NLRP3,TNF-α mRNA levels of IL-6,IL-17,IFN-y etc.)and are restored by DSS upregulates protein levels to close to normal values.It was suggested that JPE interacted with intestinal flora to alleviate DSS-induced ulcerative colitis through the NLRP3/oxidative stress pathway.(4)Study on the in vivo metabolic process of monomeric phenol caffeic acid in jujube polyphenol extract.The characteristics of two strains that metabolize caffeic acid isolated from human intestinal feces were analyzed by cell structure,16S rDNA sequence and phylogenetic tree The total number of bacteria and pH changes during the metabolism of caffeic acid by the two strains were studied,and finally the metabolites were determined by thin layer chromatography and high-performance liquid chromatography.The results showed that the two isolated strains were Staphylococcus aprophyticus and Proteus mirabilis strain。Caffeic acid inhibited the proliferation of intestinal bacteria,and the pH first decreased and then increased,and the concentration of m-coumaric acid reached a peak of 0.045 mg/mL at 12 h,and Caffeic acid was metabolized by Proteus mirabilis at 12 h,and the concentration reached a peak of 0.041 mg/mL at 24 h It showed that the ability of Staphylococcus saprophytic acid to metabolize caffeic acid was better than that of Proteus mirabilis,and the product of caffeic acid metabolized by intestinal bacteria was mcoumaric acid,which provided a basis for further research on the interaction between caffeic acid and intestinal bacteria to improve ulcerative colitis.