Study On The Hypoglycemic Effect Of Resistant Dextrin In Diabetic Mice

With economic development and the acceleration of the pace of life,the number of chronic diseases in my country has been rising,reaching about 300 million people,of which the number of diabetic patients is close to 141 million,ranking first in the world.At present,the treatment of type Ⅱ diabetes mellitus includes drug therapy,exercise therapy and dietary therapy.Among them,dietary therapy has been paid more and more attention due to its advantages of safety,effectiveness,less toxic and side effects.Previous studies have shown that resistant dextrin can improve the body’s blood glucose metabolism,but its hypoglycemic mechanism is still unclear.Therefore,based on in vitro simulated digestion,animal experiments,and combined with intestinal flora analysis,metabolomics,the hypoglycemic effect and mechanism of resistant dextrin was systematically studied in this study,providing theoretical basis for the further research and development of plant-derived hypoglycemic foods.The research content and results are as follows:(1)The rheological properties and structural characterization of resistant dextrin were systematically analyzed: the viscosity change of resistant dextrin at 20°C-60°C was studied by using a multifunctional rheometer.The viscosity of dextrin-water solution decreased gradually with the increase of temperature and finally tended to be stable,and the viscosity of highconcentration resistant dextrin-water solution was higher than that of low-concentration resistant dextrin-water solution;at 25°C,the resistant dextrin-water solution exhibited shear thinning at low shear rates(<1 /s),after which the viscosity no longer changed significantly;the microstructure of resistant dextrin was observed by thermal scanning electron microscope,and the results showed that the morphology of resistant dextrin was unequal in size and granular.The surface was uneven,scratched,rounded,or even damaged.The results provide basic data for further research on resistant dextrin.(2)In vitro simulated gastrointestinal digestion and in vitro fermentation experiments were used to study the digestive properties of resistant dextrin.Treated by compound enzyme in vitro hydrolysis,the glycemic index(GI)value of resistant dextrin was proved to be 52.75,which belongs to low GI food;the simulated digestion results in vitro showed that only a small part of resistant dextrin could be in gastric juice and intestinal juice,and the hydrolysis rates were 0.67%and 4.52%,respectively;in addition,compared with the control group,resistant dextrin could significantly increase the content of acetic acid and butyric acid in vitro fermentation experiments.(3)The effect of resistant dextrin on the health of type Ⅱ diabetic mice was studied using db/db diabetic mice.The db/db diabetic mice were randomly divided into diabetic group(DM)and 5% resistant dextrin intervention group(DRD),and continuously fed for 32 weeks.The results showed that the resistant dextrin could effectively reduce diet and body weight in mice with typeⅡ diabetes mellitus;significantly improved the blood glucose,blood lipid,and liver function of diabetic mice;In addition,resistant dextrin could repair to a certain extent pathological damage to the liver,kidney,pancreas,skeletal muscle tissue;resistant dextrin increased the content of shortchain fatty acids(SCFAs),including propionic acid,isobutyric acid and valeric acid in the intestinal contents of type II diabetic mice.(4)The 16 S rRNA sequencing method was used to compare the microbial communities in the intestinal contents of the three groups of mice.Resistant dextrin intervention could improve the diversity of gut microbiota and the intestinal flora composition of type Ⅱ diabetic mice,mainly including down-regulate the relative abundance of g＿Escherichia＿Shigella、f＿Clostridiaceac＿1;up-regulate the relative abundance of g＿uncultured＿bacterium＿f＿Muribaculaceae 、g＿uncultured＿bacterium＿f＿Lachnospiraceae 、 g＿Parabacteroides 、 g＿Ruminiclostridium＿5 、f＿Prevotellaceae、g＿Alloprevotella、f＿Christensenellaceae.(5)The serum metabolome of mice was analyzed by ACQUITY UPLC I-Class plus ultrahigh performance liquid phase tandem QE high-resolution mass spectrometer technology.The experimental results showed that: different groups of mice serum metabolites were obviously separated in the principal component analysis plots.Resistant dextrin could recall the levels of phosphatidylcholine,lysophosphatidylcholine,arachidonic acid metabolites in type II diabetic mice.The correlation analysis of metabolites and intestinal flora showed that: resistant dextrin could regulate microorganisms such as g＿Parabacteroides,g＿uncultured＿bacterium＿f＿Lachnospiraceae,and g＿Ruminiclostridium in the intestine,which involved in glycerophospholipid metabolism signal pathway,and then regulate the level of glucose and lipid metabolites in the body to improve type Ⅱ diabetes.