Abstract:In this study, probiotics with strong cholesterol-lowering ability were screened from five probiotics by using MRS-cholesterol liquid medium containing cholesterol micelles, and the selected probiotics were tested for their acid and bile tolerance. The results demonstrated that all the five strains exhibited cholesterol-lowering function, with the Lactobacillus casei (LCA-1), Lactobacillus rhamnosus (LR-D) and Lactobacillus plantarum (LP-C) having higher cholesterol degradation rates (as 25.26%, 22.18% and 20.03% respectively). LR-D could tolerate a low pH environment for a short time period but exhibited poor bile salt tolerance, with a survival rate of 14.39% after a 2 h culture in the fermentation broth at pH 2.5. LP-C could tolerate a low acid environment for a long time period and exhibited strong bile salt tolerance, with a survival rate of 133.75% and the viable cell number of 1.13×105 cfu/mL after being cultured in high bile salt medium (0.5%) for 2 h and 24 h, respectively. In these cases, the other two strains remained undetected. These results indicated that LP-C could tolerate the high bile salt environment. LP-C possessed a high cholesterol-removing rate and could withstand a low pH and high bile salt environment. Therefore, this probiotic can be used for further research and development.
