Use of Tween 80 to enhance bile tolerance of Lactobacillus reuteri

The purpose of this work was to investigate the effects of Tween 80 on bile tolerance of L. reuteri. Six strains of Lactobacillus reuteri (CF2F, DSM20016, MF14C, MM7, MM 2-3, and SD2112) were used. These strains were grown in modified trypticase-protease peptone-yeast extract (TPY) broth containing 0.0 or 0.3% bile alone or in combination with Tween 80. The extent of bacterial growth was monitored by measuring the optical density (OD) at 610 nm at various time intervals. Results showed that bile salts at 0.3% caused a significant reduction in the growth of all tested strains (P< 0.001). However, the addition of Tween 80 enhanced the bile tolerance of L. reuteri and consequently reduced the inhibitory effect of the 0.3% bile salt solution to levels comparable to growth in the absence of bile salts for three of the tested strains: MM7, CF2-7F, and SD2112. These results demonstrate that Tween 80 can be used to counter the inhibitory effects of bile salts on some strains of L. reuteri and thus can be used as a supplement to improve the bile tolerance of these probiotic bacteria.