Effect Evaluation And Application Research Of Morchella Esculenta Polysaccharide On Alleviating Obesity Induced By High-fat Diet In Mice

Obesity is a metabolic disease caused by multiple factors,mainly manifested by the accumulation of lipids in the body.It is expected that by 2025,the obese population will account for approximately 20%of the global population(with approximately 1 billion obese individuals).According to reports,the emergence and development of obesity are closely related to the gut microbiota.Long term obesity can lead to structural imbalances in the gut microbiota,with a decrease in probiotics and an increase in harmful bacteria exacerbating the symptoms of obesity.A large amount of lipids accumulate in the liver,causing liver cell lipid deformation,liver damage,and liver inflammation,leading to abnormal lipid metabolism in the body.Adjusting the gut microbiota through diet can effectively alleviate obesity.China is the country with the largest production and sales volume of edible mushroom,and polysaccharides are one of the main active ingredients of edible mushroom.Morchella esculenta is a precious edible mushroom with various biological activities.Multiple studies have reported its physiological functions such as anti-inflammatory,antioxidant,immune regulation,lipid-lowering,preventing arteriosclerosis,and alleviating obesity.However,there is a lack of research on the regulation of gut microbiota in the mechanism of alleviating obesity,and the impact on liver lipid metabolism is still unclear.Therefore,based on the study of gut microbiota,this article analyzes the effect of M.aesculenta polysaccharides on alleviating obesity through the relationship between microbiota metabolites liver lipid metabolism.And we will develop a synbiotic formulation that has the effect of alleviating obesity by compounding probiotics with M.aesculenta polysaccharides,in order to provide a theoretical basis for studying the regulatory mechanism of M.aesculenta polysaccharides on obesity.The main research content is as follows:The M.esculenta polysaccharide(MPF)was separated and purified using an anion exchange column,and four components were obtained,namely MPF-0,MPF-1,MPF-2,and MPF-3.Characterization of its structure was carried out through molecular weight,monosaccharide composition,and FT-IR analysis.MPF is a type of the molecular weight between 1.3×10~4and 5.3×10~5Da,a high molecular polysaccharide mainly composed of galactose,glucose and mannose.Collect feces from the population and add MPF for in vitro simulated colon fermentation.The results indicate that MPF can be utilized by human fecal microbiota,significantly promoting the production of short chain fatty acids(SCFAs),and at the genus level,MPF can increase the abundance of Bifidobacterium and Bacteroides.Further analysis of the abundance of different species levels within Bifidobacterium revealed that MPF can promote an increase in the abundance of B.adolescentis,B.bifidum,and B.longum.Design an animal experiment on inducing obesity in mice with a high-fat diet to explore its alleviating effect on obesity in mice.The results showed that MPF could alleviate the weight gain of mice,reduce the accumulation of white fat in the liver,epididymis,and subcutaneous tissue,increase brown adipose tissue,improve glucose tolerance,reduce blood lipids,increase liver antioxidant capacity,reduce liver inflammation,and reduce liver damage.MPF can reverse the imbalance of Firmicutes/Bacteroidetes,increase the abundance of Rikenellaceae RC9,Dubosiella,reduce the abundance of Faecalibaculum,significantly increase the levels of acetic acid and butyric acid,and reduce the content of small molecular lipids and polyunsaturated fatty acids.Reduce liver lipid synthesis gene C/ebpα,PGC-1αand PPARγ.Increase the expression of fatty acid oxidation gene ACOX1 and lipid metabolism gene PPARα.And based on correlation analysis,explore the potential mechanism of MPF in alleviating obesity.MPF can regulate the imbalance of gut microbiota caused by high-fat diet,increase the abundance of SCFAs related bacteria,increase the level of SCFAs,enter the liver through the hepatic portal vein,regulate liver lipid metabolism,reduce lipid synthesis,increase fatty acid oxidation,and play a role in alleviating obesity.Based on the above experimental results,design a hybrid of MPF and Bifidobacterium.And animal experiments were designed to evaluate the alleviating effect of obesity in mice.The three selected patented probiotics are B.adolescentis CCFM1173,B.bifidum CCFM1063and B.longum CCFM1077.After feeding three types of synbiotics,it was found that all of them could alleviate weight gain in mice,reduce white fat accumulation in the body,lower blood lipid levels,protect the liver,and reduce liver inflammation;Regulating expression of liver lipid synthesis genes,such as FASN,C/ebpα,SREBP-1c,and PPARγand expression of lipid metabolism gene PPARα;Increasing the level of SCFAs to varying degrees;All three can reverse the imbalance of Firmicutes/Bacteroides,mainly increasing the abundance of beneficial bacteria such as Dubosiella,Bifidobacterium,Bacteroides,Rikenellaceae RC9,and reducing the abundance of harmful bacteria such as Enterochabdus,Faecalibaculum,and Angelakisella at the genus level.It has been proven that three types of synbiotic preparations can alleviate obesity.Taking into account obesity related indicators and probiotic effects,the MPF+1173 group has the best relief effect.In summary,this study explains the MPF in alleviating obesity by examining the relationship between gut microbiota,metabolites,and liver lipid metabolism.Evaluates the effectiveness of three synbiotics in alleviating obesity in mice.Further provide a theoretical basis for the mechanism of MPF in alleviating obesity,enrich the mechanism of mushroom polysaccharides in alleviating obesity,and develop a synbiotic formulation containing MPF,providing scientific basis for the development of dietary supplements to alleviate obesity.