Characterization of Leuconostoc mesenteroides MJM60376 as an oral probiotic and its antibiofilm activity

Abstract

Lactic acid bacteria have been widely used as probiotics for improving gut health. However, studies on oral probiotics were very limited. In this study, 67 lactic acid bacteria (LAB) were isolated from fermented food and screened for antagonistic activity against Streptococcus mutans, the causative pathogen of dental caries. Leuconostoc mesenteroides MJM60376 showed the highest antagonistic activity against S. mutans KCTC3065. L. mesenteroides MJM60376 also showed oral probiotic characteristics including weak acid production, lysozyme tolerance, adhesion to oral epithelial cell (YD‐38), antibiotic susceptibility, and good coaggregation ability with S. mutans. Furthermore, the biofilm formation of S. mutans was significantly reduced when cocultured with L. mesenteroides. Scanning electron microscopy analysis showed that amounts of attached bacteria of S. mutans and network‐like structures were significantly reduced by L. mesenteroides MJM60376. Cell‐free supernatant (CFS) of L. mesenteroides MJM60376 also greatly inhibited biofilm formation of S. mutans from the adherent stage, the activity remained even after it was treated with catalase, trypsin, or pH neutralized. Expression levels of biofilm formation‐related genes were significantly reduced in S. mutans when it was treated with the CFS of L. mesenteroides MJM60376. Therefore, L. mesenteroides MJM60376 has great potential to be used as a multifunctional ingredient.

Heavy Ion Radiation Directly Induced the Shift of Oral Microbiota and Increased the Cariogenicity of Streptococcus mutans

“…Moreover, it is also noteworthy that in the caries-free samples, Leuconostoc significantly reduced when the radiation dose reached 80 Gy in our study. Previous studies have revealed that Leuconostoc mesenteroides shows oral probiotic characteristics and possesses strong antagonistic activity against S. mutans ( 25 ), indicating that heavy ion radiation induced an increase in cariogenic Streptococcus and also reduced their antagonistic bacteria to shift the oral microflora.…”