Investigation of the Effect of Probiotics and Specific Bacteriophages on the Biofilm Formed by Streptococcus Mutans Publisher



Dallal MMS^{1, 2} ; Reza Afraid M^{2, 3} ; Rajabi Z^{1, 3} ; Sepehri M^{3, 4} Show Affiliations
Source: Microbe (Netherlands) Published:2025

Abstract

This study investigates the effect of probiotics and specific bacteriophage on the biofilm formed by Streptococcus mutans, a bacterium strongly associated with tooth decay. Dental plaque and sewage were used to isolate Streptococcus mutans and bacteriophages, respectively. Three probiotic lactobacilli (L. plantarum, L. acidiphilus, and L. casei) previously isolated in our studies were used. S. mutans was confirmed by biochemical and molecular tests. PCR was used to detect the gtfB and gtfC genes. Bacteriophage morphology was studied using phages extracted through the double-layer agar method and TEM. The effect of probiotics and lytic bacteriophage on the formation of Streptococcus mutans biofilm was investigated by the colorimetric method with crystal violet and the real-time PCR method. Out of 60 dental plaque samples, 21 (35%) were identified as S. mutans. All of them contain the gtfD gene, and the frequency of other genes was as follows: gtfB 38 (63.33%), gtfC 33 (55%). S. mutans had strong power to form biofilm. The impact of Lactobacilli cell-free supernatant and bacteriophage on the growth and biofilm formation of isolated S. mutans resulted in a significant reduction in biofilm formation and gene expression levels. The inhibitory effect of bacteriophage was the most effective. The study's results indicate that bacteriotherapy, which involves the use of probiotics and specific bacteriophages against S. mutans, could be a promising approach to combat and reduce the formation of biofilms by S. mutans, as well as to decrease dental plaque and dental disease © 2025 The Author(s)