The In Vitro Study On Regulation Of Intestinal Microbes In Diabetic Rats By The Combination Of Baicalein And Acarbose

As the most complex micro-ecosystem in the human body,the intestinal microbiota plays an important role in balancing host health and disease.The disorder of intestinal microbiota dysregulation can trigger a series of metabolic diseases,such as diabetes.Recent studies have shown that clinical drugs for the treatment of diabetes and natural products with hypoglycemic activity affect the composition of intestinal microbiota.The regulation of intestinal microbiota has become one of the strategies for treatment of diabetes in the furture.The previous experiments proved that baicalein has inhibitory activity on?-glucosidase,and can synergistically reduce postprandial blood glucose combined with acarbose in diabetic mice.However,whether there is a difference between starch hydrolysate under the action of baicalein and acarbose,and the effect of the combination of the two on the intestinal microbiota of diabetic mice has not been reported.In response to the above questions,this paper has carried out the following studies:Firstly,a new method to detect oligosaccharides was established and an in vitro system to simulate the hydrolysis of starch was constructed.The composition of hydrolysates of starch producted by acarbose and baicalein inhibiting?-glucosidase were analyzed.The results showed the IC₅₀ values of acarbose and baicalin on the small intestinal mixed enzyme of starch as substrate were 0.36±0.08?M and 303.44±16.12?M,respectively,with combination index?CI?between 0.43 and 0.58.The composition of hydrolysates of starch producted by acarbose and baicalein by inhibiting?-glucosidase were different,where the difference increased with the increase of concentration of inhibitor.When the inhibition rate was 80%,the ratios of glucose,maltose,maltotriose,maltotetraose and starch in the acarbose-inhibiting group and the baicalin-inhibiting group were 1:0.4:1.6:3.1:10 and 1:2.7:3.1:5.2:1.2,respectively.Secondly,a culture method for culturing the intestinal microbiota was constructed.The results showed that the number of microorganisms and the concentration of short-chain fatty acids produced in GAM medium were the highest,and the microbipta diversity was significantly higher than that of YCFA and BNM.The composition of microbiotal community in GAM was the closest to that of fecal sample.Therefore,GAM medium was selected as the optimum medium for culturing intestinal microbiota.The culture conditions were liquid culture,1%inoculation,and shaking at 24 rpm for 24 h at 37°C.Finally,the mechanism of in vitro regulation of intestinal microbes by acarbose and baicalein was investigated.The results showed that Bacteroides was significantly positively correlated with gas production;Odoribacter?Morganella and Muribaculaceae showed a significant positive correlation with short-chain fatty acids production.Acarbose and baicalein and their starch hydrolysate can increase microbial diversity,the ratio of Bacteroidetes to Fiemicutes,and SCFA production.Acarbose-acting starch hydrolysate significantly increased Bacteroides to increase gas production,and baicalein reduced the ratio of hydrogen.This study demonstrated that acarbose and baicalein can affect starch hydrolysate to regulate intestinal microbiota,and provided a basis for investigating the effects of acarbose and baicalein on the regulation of intestinal microbiota in vivo.