Screening Of Cholesterol-lowering Probiotics And The Efficacy Of Lactobacillus Paracasei Jlus66 On Non-alcoholic Fatty Liver

Non-alcoholic fatty liver disease?NAFLD?refers to the clinical pathological syndrome characterized by excessive deposition of fat in liver cells caused by alcohol and other definitive liver damage factors.At present,NAFLD is the most common cause of chronic liver disease in Western countries and is expected to become the most common symptom of liver transplantation by 2030.At present,there is no clear treatment.Therefore,effective intervention in non-alcoholic fatty liver is of great significance.It is well-known that cholesterol-lowering activity is one of the most important beneficial effects of probiotics,followed by antihypertensive activity.Therefore,the screening of cholesterol-lowering probiotics also provides a good basis for the development of probiotic-type functional foods.In this paper,we use?milk pimple?as a raw material in Jilin City,Jilin Province to screen effective cholesterol-lowering lactic acid bacteria.The effects of L.paracasei Jlus66 on non-alcoholic fatty liver disease were studied by establishing a non-alcoholic fatty liver model induced by high-fat diet and a hepatocyte steatosis model induced by oleic acid and palmitic acid lipid medium.The main research contents and results are as follows:1.Screening of cholesterol-lowering probioticsSix probiotics?Jlus12,Jlus38,Jlus66,Jlus71,Jlus73 and Jlus86?were isolated from the local fermented milk.Jlus66 showed high tolerance in simulated gastrointestinal and bile salts.High hydrophobicity experiments demonstrate intestinal adhesion.In conclusion,it has good probiotic properties and was identified as L.paracasei by 16S DNA.The cholesterol removal rate in vitro was as high as 61.40%.2.Effect of Lactobacillus paracasei Jlus66 on rat model of NAFLD?1?Compared to the high-fat diet group,rats taking 4x10¹⁰ cfu Jlus66 had reduced body weight,decreased hepatic index,serum triglycerides?TG?,low-density lipoprotein?LDL?,and transaminases?ALT?significantly.Histopathological analysis showed that Jlus66 effectively reduced hepatic triglyceride,ie,steatosis and inflammation levels.?2?Lactobacillus paracasei Jlus66 reduced oxidative stress in NAFLD rats.Compared with the HFD group,the rat serum and liver malondialdehyde?MDA?content in the test 4×10¹⁰ cfu Jlus66 was significantly reduced with the activities of superoxide dismutase?SOD?and glutathione peroxidase?GSH-Px?increased.?3?Lactobacillus paracasei can effectively improve the intestinal microbiota.To regulate serum lipopolysaccharide?LPS?concentrations,the structure of intestinal flora of the high-dose intervention group was changed.L.paracasei Jlus66 reduced the abundance of pathogenic bacteria?Proteobacteria and Fusobacteria?and increased the probiotic bacteria?Lactobacillus,Bifidobacterium?reverses NAFLD.3.Intervention of Lactobacillus paracasei Jlus66 supernatant and bacterial co-culture on hepatocyte steatosis in miceWhen the dilution of the Lactobacillus paracasei supernatant was 1/32 to 1/2 and the bacterial co-cultured concentration was 10² to 10¹⁰ cfu/mL,the steatosis of the cell model could be improved.When the dilution of the supernatant was 1/2,the lipid content in the steatotic cells was reduced by 21.90%;the most significant effect was38.88%of 10¹⁰ cfu/m L.In summary,L.paracasei Jlus66 has a potential intervention effect on NAFLD.