Inhibitory potential of the probiotic Lactobacillus reuteri Biogaia Prodentis® on Streptococcus mutans

Abstract

Introduction: Probiotics are a promising alternative to control cariogenic microflora because they are effective in other systems of the body.

Objective: To evaluate the inhibitory potential of the probiotic Lactobacillus reuteri BioGaia Prodentis® on Streptococcus mutans.

Material and method: Experimental, prospective study. Two presentations of Lactobacillus-reuteri Biogaia-Prodentis® (tablet and solution) were evaluated. The solution was analyzed in a range of 1.5×106 to 1×108 CFU/mL, the tablets were rehydrated in 1g/5mL of sterile water. The growth of Lactobacillus-reuteri in selective agar was identified. Diffusion tests were carried out in agar, microdilution and MTT, using S. mutans cultures.

Results: The diffusion tests in agar did not show evident halos in the groups with probiotics, however, a qualitative alteration in the growth of S. mutans around them was identified. The micro-dilution assay with the solution showed a decrease in S.mutans growth from 1.5×106CFU/mL. Intermediate concentrations (up to 2.5×107CFU/mL) maintained a reduced but stable growth (~75–85%); tablets at 2×107CFU/mL showed a CIM (~50%). The MTT-bacterial confirmed these findings (p < 0.05).

Conclusion: Both formulations of the probiotic showed ability to inhibit the growth of S.mutans. The solution showed earlier inhibition, while the tablets were more effective at high concentrations.