In vitro Screening of Probiotics with Cholesterol-Reducing Potential Abilities and Study on its Cholesterol-Reducing Mechanism

Abstract:

The lactobacilli which has high cholesterol uptake and utilization rate are isolated after screening. Their cholesterol-reducing mechanism is detected in vitro，to provide a theoretical basis for cholesterol-reducing fermented food research and development. The probiotic strains with cholesterol-reducing activity are first obtained by screening. Then the saponification-colorimetric screening is performed to obtain lactobacillus strains with high cholesterol absorption efficiency. The lactobacilli has cholesterol-reducing rates ranged from（3.30±0.89）%~（75.64±1.12）%，with the average rate of 44.34%. Among them，14 strains have higher cholesterol-reducing rate than average. Lb. plantarum S11 is the strain with the cholesterol-reducing rate as high as（75.64±1.12）%. It is indicated that only 0.002 mg of cholesterol is adsorbed and precipitated by 4.20×109 cfu/mL of Lb. plantarum S11 cells by determine the content of cholesterol in the suspension of the disrupted cells（only 1.30%）. This results indicate that the cholesterol-reducing activity of Lb. plantarum S11 is achieved mainly by absorbing and assimilation，but not absorbing and incorporating in cell membrane.The screening and isolation methods in this study can be applied to select cholesterol-reducing probiotics from traditional fermented foods. And it is also helpful for follow-up development of new cholesterol-reducing lactobacilli fermented products.