Inhibitory Effect of Probiotic Strains of Lactobacillus reuteri DSM 17938 Derived from Biogaia against Streptococcus mutans: An in Vitro Study

Oral infections are considered a serious public health problem, the purpose of this research was to determine the inhibitory effect of probiotic strains of Lactobacillus reuteri DSM 17938 derived from Biogaia against Streptococcus mutans developed in vitro at different concentrations at 24 and 48 h. Application study, experimental design, longitudinal chronology, and prospective measurement. The Petri dishes were divided into groups of different concentrations of the isolated strain Lactobacillus reuteri obtained by culturing the commercial product Biogaia protectis, the sample was selected by convenience according to the study criteria. 8 Petri dishes were cultivated with three replicates where the Kirby Bauer disk diffusion technique was applied to see the sensitivity of the inhibition halo and modified agar wells, making a total of 64 disks and wells; Petri dishes were divided into groups of different concentrations of 100%, 75%, 50%, and 25%. Growth turbidity was expressed as means ± standard deviations (SD), for data analysis. The analysis of variance (one-way ANOVA) and the statistical t-test were applied, and the experiment was carried out in triplicate, considering p-values less than 0.05 statistically significant. The best inhibitory effect is registered by the Lactobacillus reuteri bacterium at a concentration of 100% at 48 h against Streptococcus mutans bacterium with an average of 17.50 mm of inhibition halo, its standard deviation being ± 0.24 in relation to the average.