Evaluation of the anti-Helicobacter pylori and cytotoxic properties of the antimicrobial substances from Lactobacillus acidophilus BK13 and Lactobacillus paracasei BK57

Abstract

The objective of this study is to investigate the anti-Helicobacter pylori and anti-cancer activities of the live cells (LC), cell-free culture supernatants (CFCS), and bacteriocin solution (BS) obtained from Lactobacillus acidophilus BK13 and Lactobacillus paracasei BK57 strains. After incubation for 30 h in MRS broth, the concentration of lactic acid produced by L. paracasei BK57 (155.9±10.2 mM) was higher than in MRS broth using L. acidophilus BK13 (126.8±7.9 mM). Maximum bacteriocin activity (128 AU/ml) of BK13 strain was observed after 30 h of cultivation at 37°C, however its magnitude was significantly lower than that of BK57 strain (256 AU/ml). The LC of L. acidophilus BK13 and L. paracasei BK57 were able to inhibit the growth of H. pylori ATCC 43504 at different incubation times, depending on the initial inoculum of the LAB. These CFCS and BS obtained from BK13 and BK57 strains dramatically inhibited the growth, adhesive ability, and enzymatic activity of H. pylori. Meanwhile, the anti-cancer effect of the lactic acid from L. acidophilus BK13 and L. paracasei BK57 strains on AGS cells had significant differences with the control group. Therefore, these antagonistic substancesproducing strains are potentially useful as new potential antimicrobial agents for the management and prevention of H. pylori infections.