Effect Of Polysaccharides From Different Species Of Edible Mushrooms On Lipid-lowering Effect And Intestinal Flora In Mice Fed With Hight-fat Diet

According to the "Report on the Status of Nutrition and Chronic Diseases of Chinese Residents(2020)",more than 1/2 of adults in China are overweight or obese,with overweight and obesity rates of 34.3% and 16.4% respectively.Obesity has become an important factor threatening human health,weight loss drugs and surgery have greater side effects,and many edible fungus polysaccharides have shown safe and efficient weight loss and metabolic regulation in anti-obesity.At present,there is limited research on Tricholoma matsutake,Tuber sinense and Pleurotus citrinopileatus polysaccharides,mainly in vitro antioxidant,anti-tumor and other aspects.Our previous in vitro experiments have shown that Tricholoma matsutake,Tuber sinense and Pleurotus citrinopileatus polysaccharides have no toxic effect on macrophages RAW264.7,and can promote the proliferation of macrophages RAW264.7,improve the phagocytic neutral red ability of macrophages RAW264.7,and increase the amount of NO produced.In this paper,the ultrasound-assisted water extraction alcohol precipitation process established by the research group was used to extract crude polysaccharides from Tricholoma matsutake,Tuber sinense and Pleurotus citrinopileatus,and the anti-obesity effects and intestinal flora of different doses of Tricholoma matsutake,Tuber sinense and Pleurotus citrinopileatus polysaccharides were studied.The main research contents and results are as follows:1.Gastric gavage intervention was performed on high-fat diet mice using low,medium and high doses(50 mg/kg,100 mg/kg and 200 mg/kg)of Tricholoma matsutake,Tuber sinense and Pleurotus citrinopileatus polysaccharides,and the weight change,feed intake and water intake of mice were recorded,and the growth performance of mice was measured after 10 weeks.The results showed that the weight of ND mice and HFD mice at week 10 was 25.46 ± 0.9 g and 32.28 ± 0.90 g,respectively,and the average daily feed intake of HFD mice after polysaccharide intervention was significantly lower than that of the model group(P < 0.05),and TMP,TSP and PCP reduced the body weight of mice by reducing fat intake,without affecting the average daily water intake of mice.TMP 50,TSP 200 and PCP 100 had the best effect on reducing the body weight of mice in the polysaccharide treatment group(P < 0.01),and the body weight of mice was 29.27 ± 1.30,30.13 ± 1.44 and 28.62 ± 1.01 g,respectively.2.Measurement of serum biochemical indexes of mice after the 10 th week of the trial,the results showed that TMP 100 and TMP 200 could reduce total cholesterol(Total cholesterol,TC),total triglycerides(Total triglycerides,TG)and low density lipoprotein cholesterol(Low density lipoprotein cholesterol,LDL-C)levels in HFD mice;Both high,medium and low doses of TSP can reduce LDL-C content;PCP 50 and PCP 100 in the PCP group reduced LDL-C content.The effect of the three polysaccharides on high density lipoprotein cholesterol(HDL-C)levels was not significant.High-fat diet had an effect on glucose metabolism homeostasis in mice,and only low doses of TSP and PCP in the first oral glucose tolerance test could improve glucose tolerance in HFD mice(P < 0.05),and high,medium and low doses of TMP,TSP and PCP in the second oral glucose tolerance test could significantly(P < 0.01)enhance glucose tolerance in HFD mice.3.The inhibitory effects of TMP,TSP and PCP on chronic inflammation and oxidative stress in HFD mice were studied by enzyme-linked immunosorbent assay(ELISA).The results showed that TMP,TSP and PCP interventions could significantly reduce the levels of pro-inflammatory factors IL-1β,IL-10 and TNF-α in the serum of HFD mice(P < 0.01),as well as the content of LPS,a possible trigger for serum inflammation,and reached extremely significant levels(P < 0.01)at both high and low doses.TMP,TSP and PCP significantly increased the activity of serum antioxidant enzymes SOD,GSH-Px and CAT(P < 0.05).4.Real-time PCR was used to study the relative expression levels of TMP,TSP and PCP on the genes PPARγ,FAs and CPT-1 m RNA related to colon lipid metabolism in HFD mice.The three dose groups of TMP,TSP and PCP could inhibit the elevated expression of PPARγ and FAs caused by high-fat diet(P < 0.01)at the m RNA level and significantly increase the expression level of CPT-1 m RNA(P < 0.05).The results showed that TMP,TSP and PCP could exert lipid-lowering effects by regulating the expression of these genes.5.16 s r RNA sequencing of mouse cecal contents after 10 weeks of trial by Illumina Miseq PE250 high-throughput sequencing platform,and bioinformatics analysis of sequencing data.The high-fat diet increased the abundance of Firmicutes in HFD mice and increased the ratio of Firmicutes to Bacteroidetes.TMP,TSP and PCP interventions reversed HFD-induced increase in F/B ratio,and at the genus level,TMP,TSP and PCP interventions increased the abundance of some beneficial microorganisms such as Akkermansia in the gut and reduced the abundance of harmful microorganisms such as Helicobacter.No beneficial effects of TMP,TSP and PCP on Bifidobacterium and Lactobacillus were found,and TMP,TSP and PCP treatment did not restore the increase in the intestinal microbiota category of mice caused by the high-fat diet,but recovered the changes in the microbiota structure.