Study on cholesterol removal by Lactobacillus reuteri and its survival in simulated gastrointestinal tract and yogurt

In this study, capability to remove cholesterol, acid tolerance, bile salt tolerance and viability in yogurt of Lactobacillus reuteri (DSM 20016) were examined. Results showed that L. reuteri was able to remove 58.96 μg/ml of cholesterol from culture medium containing 100 μg/ml cholesterol and 0.3 % (w/v) of bile salt. Also, after 2 hours at pH 2, the viable count of L. reuteri declined to 3.3 from 8.1 log cfu/ml. In order to study bile tolerance, the growth rate of bacteria was determined in MRS broth containing 0.3% (w/v) bovine bile salt (oxgall). Results illustrated that L. reuteriwas resistant to the bile salts. Finally the viability of L. reuteri in yogurt throughout the storage was examined. Results revealed that L. reuteriadequately maintained its viability throughout the storage period, so that after 3 weeks of storage, the number of viable bacteria was over recommended level of 106cfu/ml. Therefore, L. reuteriwas regarded as a suitable probiotic for production of cholesterol-lowering yogurt.