Abstract:Excessive cholesterol intake may lead to cardiovascular and cerebrovascular health problems. Lactic acid bacteria can regulate the absorption and metabolism of cholesterol in the body by regulating the expression of cholesterol metabolism related genes in the small intestine, thus affecting the cholesterol content in the body. In this study, 15 lactic acid bacteria isolated from traditional fermented meat products were screened for cholesterol-lowering ability, acid and bile salt tolerance in vitro, and the screened lactic acid bacteria were used in animal experiments. The results showed that 4 of the 15 lactic acid bacteria (CM6, CM9, CM28, CM42) had good cholesterol-lowering ability in vitro, and the average degradation rate was 52.92%. Acid and bile salt tolerance tests were carried out on these four lactic acid bacteria strains, among which strain CM6 could reach 106 CFU/mL at pH 2 and 0.3% bile salt addition. Finally, CM6 was selected for subsequent animal experiments. After 30 days of intragastric administration of lactic acid bacteria, the contents of total cholesterol and triglyceride in serum of mice in the lactic acid bacteria group were significantly lower than those in the control group(P < 0.05). The relative expression of NPC1L1 gene in the small intestine of the lactic acid bacteria group was significantly lower than that of the control group(P < 0.05), and the expression of ABCG5 / G8 gene was significantly higher than that of the control group(P < 0.05). The results showed that lactic acid bacteria CM6 had the ability to regulate the expression of cholesterol metabolism-related genes, thereby reducing the cholesterol content in the body.