| Objective: This paper uses three different interventions on obese rats induced by high fat diet,which are aerobic exercise,composite plant polysaccharide gavage,aerobic exercise combined with composite plant polysaccharide gavage,to observe effects of different intervention methods on morphological indexes,regulatory factors of plasma lipid metabolism,and metagenomics analysis of fecal samples from each group.With a view to interpreting the possible differences in the role of the above interventions in the process of weight loss and fat reduction targeted at gut microbiota,and to provide experimental data support.Methods: There were 50 male Sprague-Dawley rats for this experiment.Randomly select 8 of which as the normal control group(N=8),the rest was used as a high fat diet to induce obesity group.After feeding with high fat diet for 4 weeks,the obese rats whose body weight was 20% higher than the average weight of the normal control group were selected.They were randomly divided into obesity control group(N=8),aerobic exercise intervention group(N=8),compound polysaccharide intervention group(N=8)and aerobic exercise + compound polysaccharide intervention group(N=8).The animals in the corresponding groups were intervened by moderate intensity aerobic exercise,compound plant polysaccharides intragastric administration and the combination of the two methods for 6 weeks.After the intervention,the anaesthetized rats were anesthetized,the body weight and length of rats were accurately weighed,and the Lee’s index was calculated.Apical blood was collected for determination of PPAR-γ,LPL and LEP in plasma.The perirenal and epididymal fat pads of rats were removed and stained with hematoxylin-eosin,and the size of fat droplets in adipocytes was observed.The feces of all rats were taken for metagenomic gut microbiota sequencing.All the tested data were statistically analyzed to meet the normal distribution,and the significant differences between groups were compared by univariate analysis of variance,and then group O was used as the control group to use Bonferroni post-test for pairwise comparison.It does not satisfy the normal distribution data,and the rank sum test is used to analyze the differences between groups.Finally,the correlation analysis of each significant difference index data was carried out,and the significance level was set as P < 0.05.Results:1.Changes of morphological indexes,Compared with the normal control group,the body weight of obese rats increased significantly(P<0.01),Lee’s index also increased.The volume of adipocytes in perirenal and epididymis increased significantly,the shape was more irregular,and the boundary between cells tended to be blurred.Compared with the obesity group,the body weight and Lee’s index of rats in the aerobic exercise group decreased significantly(P<0.05).The adipocytes in perirenal and epididymis of obese rats were significantly smaller,the arrangement of adipocytes became closer and closer,and the boundary between cells tended to be clear after intervention in all three ways.2.Changes of regulatory factors related to lipid metabolism,Compared with the normal control group,the plasma concentrations of PPAR-γ and LEP in the obese group were increased significantly(P < 0.001),while the LPL concentration was decreased significantly(P < 0.001);Compared with the obesity group,The concentration of PPAR-γ in plasma of rats in aerobic exercise group decreased significantly(P<0.01).The concentrations of PPAR-γand LEP in plasma of rats in compound polysaccharide group decreased significantly(P<0.001).The concentration of PPAR-γ in plasma of rats in aerobic exercise + compound polysaccharide group decreased significantly(P<0.01).3.Results of species difference analysis of gut microbiota by metagenomic sequencing,the number of bacteria with significant differences amongnormal control group,obesity control group,aerobic exercise intervention group,compound polysaccharide intervention group and aerobic exercise and compound polysaccharide intervention group.There were significant differences in the number of bacteria among groups: 18,13,2,8 and 13,respectively.(1)At the Genus level,Compared with the normal control group,the abundance of Akkermansiain intestinal tract of obese rats decreased significantly(P < 0.05).Compared with the obese group,the abundance of Prevotella in intestinal tract of rats in aerobic exercise group increased significantly(P < 0.05).The abundance of Bifidobacterium in intestinal tract of rats in compound polysaccharide group was significantly increased and the abundance of Alistipes was significantly decreased(P<0.05).The abundance of Bacteroides fragilis in intestinal tract of rats in aerobic exercise+ compound polysaccharide group increased significantly,while the abundance of Alistipes decreased significantly(P<0.05).(2)At the Species level,Compared with the normal control group,the abundance of Akkermansia mucinphila,Alistipes finegoldii,Bacteroides ovatus and Gramnegative bacterium c L10-2b-4 in the intestine of obese rats decreased significantly(P<0.05).Compared with the obese group,the abundance of Prevotella copri,Prevotella denticola and Prevotella melaninogenica in the intestinal tract of rats in the aerobic exercise group increased significantly,while the abundance of Oscillibacter valericigenes decreased significantly(P<0.05).The abundance of Bifidobacterium animalis in intestinal tract of rats in compound polysaccharide group was significantly increased,while the abundance of Alistipes shahii was significantly decreased(P<0.05).The abundance of Alistipes shahii in intestinal tract of rats in aerobic exercise +compound polysaccharide group was significantly decreased,while the abundance of Bacteroides fragilis was significantly increased(P<0.05).4.Statistical analysis of differential genes in metabolic pathways associated to metagenomic sequencing,The effects of metabolic genes of different modules in different databases of gut microbiota between obese rats and other groups of rats were different,and there were significant differences.Compared with the normal control group,the related gene expression of Arginine and proline metabolism,Vibrio cholerae pathogenic cycle,Staphylococcus aureus infection and Various types of N-glycan biosynthesis in intestinal samples of obese rats were significantly up-regulated.Compared with the obese group,the related gene expression in Inositol phosphate metabolism,Salmonella infection and Various types of N-glycan biosynthesis in intestinal samples of rats in aerobic exercise group were significantly down-regulated.The related gene expression in Vibrio cholerae pathogenic cycle in compound polysaccharide group was significantly down-regulated.(P<0.05).In the intestinal samples of rats in the aerobic exercise + compound polysaccharide group,the related gene expression of Salmonella infection was significantly down-regulated(P<0.05).5.Results of correlation analysis,The concentrations of PPAR-γand LEP in plasma were positively correlated with the changes of body weight in rats(P<0.05).The abundance of Gram-negative bacterium c L10-2b-4 in rat intestine was negatively correlated with LEP,PPAR-γ,CBM23,Various types of N-glycan biosynthesis and body weight,and positively correlated with LPL(P<0.05).Conclusion: The main observation of this paper is:(1)High fat diet induced significant weight gain,disorder of lipid metabolism regulatory factors and morphological changes of adipocytes in obese rats.The structural imbalance of gut microbiota and abnormal expression of genes in metabolic pathway are important factors to induce phenotypic changes.(2)Aerobic exercise,intragastric administration of compound polysaccharides and their combined intervention can effectively improve the body phenotype of obese rats,improve the imbalance of gut microbiota and regulate the abnormal expression of gut microbiota metabolic pathway genes in obese rats.finally,it was effectively transferred to the concentration of lipid metabolism-related regulatory factors in plasma.It was observed that the improvement of obesity phenotype was different in different intervention methods,and there were significant differences in the regulation of intestinal flora and genes related to metabolic pathway.The further interpretation of the above differences needs to be confirmed by more in-depth transcriptome and metabonomic analysis. |
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