Significance of bile salt tolerant lactobacillus reuteri

Abstract

Probiotic supplements have received worldwide attention due to their health benefits. One of the most commonly used probiotics is Lactobacillus reuteri, which has known to help prevent and treat both viral and bacterial diarrhea enhancing the body's resistance to gastrointestinal disease. In order to survive and colonize in the gastrointestinal tract, L. reuteri should express high tolerance to bile salt. This study was therefore undertaken to determine the effect of bile salt on the growth and s-galactosidase activities of L. reuteri. The effect of Tween 80 on the promotion of L. reuteri tolerance against bile salt was also determined. Five strains (CF2F, DSM20016, MM2-3, and MM7) of L. reuteri used for this study were subjected to MRS broth supplemented with various concentrations (0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 2.0, and 4.0%) of bile salt. Bacterial growth was then monitored using a spectrophotometer (610 nm) for 10 h at 37°C. Results showed that 0.3% bile salt significantly (P<0.05) reduced the growth of L. reuteri strains. Strain MM2-3 showed higher survival and s-galactosidase activity (800 and 1500 Miller units) than other strains tested. The addition of Tween 80 enhanced the bile salt tolerance of L. reuteri. The results of this study demonstrate that bile salt and Tween 80 has an influence on the biochemical properties of L. reuteri and should be considered for useful applications in enhancing the survival of Lactobacillus. © Springer Science+Business Media, LLC 2009.