Regulation Of The High Fat-induced Obesity Formation Of In Mice By Lactobacillus Plantarum

The incidence of obesity and its associated chronic metabolic-related diseases such as fatty liver,hyperlipidemia,and type 2 diabetes is increasing,making it a health concern in the world.There are many causes of obesity,in which long-term intake of high-fat energy foods and sedentary work are the main causes of obesity.At present,there are many drug treatments and surgical treatment methods to control the body weight,but most of them are accompanied by adverse side effects,more safty and healthy non-drug therapy has been proposed,including the use of probiotics.Lactic acid bacteria are the main source of probiotics,and its fermented products have been consumed by the public for many years.It has been studied for alleviating the effects of hyperlipemia,obesity,non-alcoholic fatty liver and other diseases,mainly by Lactobacillus and Bifidobacterium,but its mechanism to alleviate the formation of obesity is not clear,and there is strain specificity.The two strains of lactic acid strains KLDS1.0344 and KLDS1.0386 in the experiment have excellent lipid-lowering ability in vitro,but the mechanism of alleviating obesity and triglyceride accumulation in vivo is still unclear.Therefore,this experiment uses Lactobacillus plantarum KLDS1.0344 and KLDS1.0386 as the starting strains,and evaluates its ability to alleviate obesity through obese mice.It explores the inhibition of triglyceride accumulation by detecting differences in fat metabolism-related genes and biochemical indicators in vivo.The aim is to provide a data reference for lactic acid bacteria to alleviate the formation of high fat-induced obesity,and provide a basis for further application of KLDS1.0344 and KLDS1.0386.First,the gastrointestinal tolerance of KLDS1.0344 and KLDS1.0386 was tested to determine whether it can ensure sufficient quantity to reach the intestinal tract.Secondly,the adhesion characteristics of KLDS1.0386 and KLDS1.0344 were detected in vivo.Adhesion and colonization are preconditions for the action of probiotics.Subsequently,C57BL/6J male mice were fed with D12492 high-fat diet to establish an obesity model.KLDS1.0344,KLDS1.0386,and the mixed bacteria were also administered at a concentration of 5×10~8 CFU/m L.The suspension was studied for 8 weeks to study the inhibitory effect of the strain on the formation of obesity in mice and the effect of the strain on the liver of obese mice.The changes of related factors in the fat metabolism pathway of mouse adipose tissue were detected by q RT-PCR;Changes in the content of short-chain fatty acids produced by microbial and intestinal metabolism in obese mice induced by high-fat diet were detected.In the simulated gastric juice at p H 3,the concentration of KLDS1.0344 was maintained at 10~9 CFU/m L after 3 h,and it was cultured in intestinal fluid and bile-containing intestinal juice for 3 h,and the bacterial concentration was still 10~9 CFU/m L.KLDS1.0386 was cultured for 3 h in simulated gastric juice at p H 3,the bacterial concentration was reduced to 108 CFU/m L,and cultured in intestinal fluid and bile-containing intestinal juice for 3 h.The bacterial concentration was 10~9 CFU/m L,indicating KLDS1.0344 and KLDS1.0386 has good gastrointestinal fluid tolerance and can ensure a sufficient number of levels to enter the intestine.In vivo adhesion experiments in mice,the results showed that KLDS1.0344 and KLDS1.0386 have certain adhesion and colonization ability in duodenum,jejunum,ileum and colon.Fluorescence detection of mouse intestinal mucosa cells by flow cytometry showed adhesion in the number of fluorescent cells detected per 10,000 intestinal mucosal cells.KLDS1.0344 was in the duodenum and jejunum on the first day.Enrichment reaches 600-1000 CFU/10,000 cells,enrichment in the ileum and colon on day 2-7,reaching 500-2000 CFU/10,000 cells;KLDS1.0386 in the jejunum and duodenum on day 1-2 The enrichment reached 400 CFU/10,000 cells,and enriched in the ileum and colon on day 3-7,reaching 500-1500 CFU/10,000 cells,and KLDS1.0344 and KLDS1.0386 were detected in 7 days.The effects of KLDS1.0344 and KLDS1.0386 on obesity formation in mice were evaluated by constructing an obese mouse model,and its possible regulation mechanism of fat metabolism was studied.After 8 weeks of gavage,the body weight,Lees coefficient and body fat percentage of KLDS1.0344 group,KLDS1.0386 group and KLDS1.0344 and KLDS1.0386 mice were significantly lower than those in the model group(P<0.05).The serum levels of TG and TC in these three groups were significantly decreased,and serum levels of HDL-C were markedly up-regulated(P<0.05).At the same time,the mixed group could effectively reduce the content of TG in the liver,relieve liver damage and oxidative stress,through the above experiments,showed that the mixed group intervention effect was the most significant.The expression of related genes in AMPK of lipid metabolism pathway in mouse adipose tissue was detected by real-time PCR.It was found that the decrease of triglyceride accumulation in KLDS1.0344 and KLDS1.0386 mixed group may up-regulate the expression of AMPK-? by activating AMPK pathway.Furthermore,the ACC gene is inhibited and the synthesis of fat is inhibited.The inhibition of ACC promotes the expression of CPT-1,increases the oxidative decomposition of fat,reduces the secretion of adipokines PPAR-?,and regulates lipid metabolism.16S rDNA of the microecology in the cecal contents of mice showed that the high-fat diet caused changes in the micro-ecology and intestinal metabolites in the intestine of mice.The intervention of the mixed group can reduce the relative abundance of the Firmicutes in the intestine,increase the relative abundance of the Bacteroides,and alleviate the increase of the proteobacteria caused by the high-fat diet.In the detection of short-chain fatty acid levels in the intestinal contents of mice,the results showed that the high-fat diet significantly decreased the content of short-chain fatty acids in the mouse contents(P<0.05),and the most significant decrease in the content of acetic acid and butyric acid;The intervention increased the total level of short-chain fatty acids,and the levels of acetic acid and butyric acid were significantly up-regulated(P < 0.05).Interventions in the mixed group may affect the body's lipid metabolism by improving intestinal micro-ecological structure and SCFAs content.Based on the above results,the following main conclusions were drawn: KLDS1.0344 and KLDS1.0386 strains have better gastrointestinal tolerance;they have certain adhesion and colonization ability in the intestine of mice;the intervention of KLDS1.0344 and KLDS1.0386 can effectively inhibit the formation of obesity induced by high-fat diet in mice,and regulate the expression of AMPK-related factors AMPK-?,ACC,CPT-1 and PPAR-? in fat metabolism pathway;KLDS1.0344 and KLDS1.0386 improve the intestinal micro-ecological structure,the content of SCFAs in intestinal contents,improve the body's energy absorption and inhibit the formation of obesity.