Screening Of Polyphenol With The Ability To Enhance The Abundance Of Intestinal Akkermansia Muciniphila And The Involved Enhancive Mechanisms

Akkermansia muciniphila(A.muciniphila)is an intestinal bacterium closely related to human health.A large number of experiments have proved that increasing the abundance of A.muciniphila in the intestine can alleviate the symptoms of obesity,alcoholic liver disease,and other diseases.However,considering the prohibition of the direct addition of A.muciniphila in food,it is necessary to explore indirect dietary regulation strategies.Given the potential role of polyphenols in increasing the proportion of A.muciniphila in the intestine,this study aimed to screen the specific phenols to explore its promotion mechanism to regulate A.muciniphila,and verify it in the disease model.First,we compared the pre-ability to regulate A.muciniphila with the post-ability to regulate A.muciniphila after a four-week-polyphenols supplement on healthy mice.Both relative and absolute quantification analysis showed that caffeic acid,chlorogenic acid,epigallocatechin gallate,procyanidin,and puerarin could significantly regulate the abundance of A.muciniphila.Additionally,chlorogenic acid could increase the relative proportion of A.muciniphila in the intestine to over 10% and the absolute abundance by one order of magnitude,with a significantly better regulation effect relative to other phenols.Oppositely,resveratrol,ferulic acid,and genistein failed to regulate the abundance of A.muciniphila.To evaluate the effect of increased abundance of A.muciniphila on the physiological health status of mice,indexes such as body weight,tissue weight,blood lipid,and blood glucose were measured on the mice.There was no significant effect on basic physiological functions of mice but the content of plasma low-density lipoprotein cholesterol was decreased and glucose tolerance was improved.Next,chlorogenic acid was settled as the research object to further explore its promotion mechanism to increase the abundance of A.muciniphila in the intestine.The direct promotion method(i.e.,adding different doses of chlorogenic acid)was not able to significantly improve the maximum biomass and growth rate of A.muciniphila.Then,we employed the indirect promotion method(i.e.,whether chlorogenic acid could stimulate the intestinal tract to secrete more mucin as the nutrients for the growth of A.muciniphila)but failed to either promote the differentiation of goblet cells or stimulations of mucin secretion.Furthermore,we investigated the synergistic and competitive relationships between flora and the promotion and inhibition relationships between metabolites.Based on the analysis of 16 S r RNA sequencing,short-chain fatty acid determination,and nontargeted metabolite,we found that chlorogenic acid intake promoted Ruminococcaceae UCG-014 and inhibited both Desulfovibrio and Alistipes;The butyric acid content was significantly increased(P < 0.01);Bile related compounds,deoxy purine nucleoside,basic group,docosahexaenoic acid,β-Hydroxybutyric acid,N-acetyl-lactosamine,and other substances were significantly enriched.Combined with bioinformatics analysis and functional genes comparison,it was speculated that chlorogenic acid increased the abundance of A.muciniphila by inhibiting Desulfovibrio and Alistipes(competitive with A.muciniphila),and enriching docosahexaenoic acid,β-Hydroxybutyric acid,N-acetyl-lactosamine,which is conducive to the growth of A.muciniphila.According to the above-mentioned findings,we verified the regulation ability of chlorogenic acid on the abundance of A.muciniphila in the obesity model.It showed that a high-fat diet reduced the abundance of A.muciniphila by about 60 times.After12-week-chlorogenic acid supplementation,compared with high-fat model mice,low-,medium-,and high-dose chlorogenic acid supplementations could significantly increase the proportion of A.muciniphila in the intestine by 8 times,16 times,and 60 times respectively.Additionally,it also manifested the functions of chlorogenic acid in reducing fat,reducing blood lipid,improving liver steatosis,and enhancing the intestinal barrier for obese mice induced by a high-fat diet.In sum,this study verified that chlorogenic acid plays the most notable role in regulating the proportion of A.muciniphila relative to other polyphenols.Specifically,the intake of chlorogenic acid may be through the inhibition of both Desulfovibrio and Alistipes,and the enrichment of docosahexaenoic acid,β-Hydroxybutyric acid,N-acetyl-lactosamine,to increase the abundance of A.muciniphila in the intestine.Chlorogenic acid largely increased the abundance of intestinal A.muciniphila and alleviated disease symptoms in obese mice.This study further explored the mechanism of phenols promoting the abundance of A.muciniphila,and provided a scientific basis for the development of dietary supplement of dietary supplements to enhance the abundance of A.muciniphila in the intestine in the future.