Study On The Effect And Mechanism Of Cyanidin-3-Oglucoside On Gut Microbiota

Existing research shows that gut microbiota is closely related to human health,and its importance is equivalent to that of human organs.Bioactive anthocyanins widely present in berries have been shown to protect and improve human health by regulating gut microbiota and its metabolites,and anthocyanins can be degraded into small molecular phenolic acids by gut microbiota parasitic in the colon.However,current research mostly focuses on the effect of anthocyanins on the composition of gut microbiota and its metabolite levels,and has not explored the form and mechanism of its effect on the gut microbiota.It is unclear whether anthocyanins affect the gut microbiota in the form of their ingested raw compounds or their degradation products.Therefore,in this study,the more common monomeric Cyanidin-3-OGlucoside(C3G)in anthocyanins and its colonic degradation products were used to culture the gut microbiota in vitro,and 16 S rRNA gene sequencing technology was used to analyze the different Changes in the gut microbiota at time points to clarify the effect of C3 G on the gut microbiota and its form of action.On this basis,bacteria with significant responses to C3 G were selected,and transcriptomic technology was used to explore the mechanism of C3 G promoting the growth of beneficial bacteria in gut microbiota.The specific conclusions are as follows:(1)C3G and its colonic degradation products have beneficial effects on gut microbiota.After the treatment of C3 G and its colonic degradation products,the diversity and richness of gut microbiota were significantly improved;both C3 G and its colonic degradation products could significantly improve the composition of gut microbiota,mainly manifested as C3 G and its colonic degradation products promote the relative abundance of beneficial bacteria in the gut microbiota,such as Parabacteroides,Lachnospira,Bifidobacterium,Dialister,Blautia,etc.,and the promotion effect of C3 G is significantly better than that of its colonic degradation products.(2)The form of action of C3 G affecting the gut microbiota is its original compound.16 S rRNA gene sequencing technology was used to analyze the change rules of C3 G and its colonic degradation products in different time periods of gut microbiota.It was found that at the family level,C3 G cultured gut microbiota for 8-12 h,and its colonic degradation products were cultured for 18 h.The effect of C3 G culture for 12 h in the gut microbiota and its colonic degradation products for 18 h have almost the same genus-level flora structure.Therefore,it can be confirmed that the form of C3 G that regulates the gut microbiota is the original compound ingested,that is,after C3 G enters the colon,it begins to act on the gut microbiota.(3)The mechanism of C3 G promoting the growth of beneficial bacteria in gut microbiota was clarified,and the mechanism of inhibiting the growth of harmful bacteria was speculated.Transcriptomic analysis of Bifidobacterium longum and Parabacteroides distasonis exposed to C3 G showed that after the action of C3 G,a total of 286 genes were differentially expressed in Bifidobacterium longum,among which 182 genes were up-regulated and 104 genes were downregulated;a total of 527 genes were differentially expressed in Parabacteroides distasonis,among which 271 genes were up-regulated and 256 genes were down-regulated.Through GO enrichment analysis and KEGG pathway analysis of differentially expressed genes,it is shown that C3 G could increase the relative abundance of beneficial bacteria in gut microbiota by promoting the protein synthesis,accelerating the growth of various organelles,inducing cell growth and the metabolism of key substances of differentiation(such as sphingolipids)of beneficial bacteria.At the same time,it can induce the carbohydrate metabolism of beneficial bacteria and promote the biosynthesis of beneficial bacteria and antibiotics.By competing with harmful bacteria for nutrients and killing pathogenic bacteria,it can reduce the relative abundance of harmful bacteria in gut microbiota and improve the composition of human gut microbiota.