Indonesian Strain of Lactobacillus reuteri Probiotic Reduces the Initial Biofilm Colonization

The benefits of probiotics for human health have long been proven. Probiotic Lactobacillus reuteri, can produce a beneficial broad-spectrum antibacterial compound called reuterin by metabolizing glycerol.

The aim of the study was to investigate the effect of the Indonesian strain of L. reuteri LC382415 on mono- and dual-species Streptococcus mutans and Streptococcus sanguinis biofilms in vitro.

Streptococcus mutans and S. sanguinis were cultured in BHI broth. Lactobacillus reuteri LC382415 was inoculated on MRS agar. The different concentrations effect of L. reuteri (1×10⁴, 1×10⁶, and 1×10⁸ CFU/mL) with and without glycerol supplementation on microbial biofilms were examined using a biofilm assay after incubation for 1,3,6, and 24-h. The biofilm mass optical density was measured with a microplate spectrophotometer at 490 nm. Chlorhexidine gluconate (0.2%) was used as a positive control, and wells without treatment were used as negative controls.

A significant reduction in mono- and dual-species S. mutans and S. sanguinis biofilm formation was observed after treatment with all concentrations of L.reuteri and after all incubation periods (p<0.05) with or without glycerol supplementation. The concentration of 1×10⁴ CFU/mL after 3-h incubation was the most effective in inhibiting biofilm formation, with 87.8% S. mutans, 95.9% S. sanguinis, and 80.4% dual-species biofilm reduction compared to the negative control (p<0.05).

The Indonesian strain of L. reuteri effectively reduces mono- and dual-species S.mutans and S. sanguinis biofilms. This suggests that it may be useful in preventing biofilm formation in oral cavities. Future studies on the mechanism of action of this active component are warranted.