The CelB Gene Mediates Erythritol-Induced Inhibition of Exopolysaccharide Synthesis in Streptococcus mutans

Streptococcus mutans is a primary contributor to dental caries due to its ability to form biofilms rich in extracellular polysaccharides (EPS). While erythritol has been recognized for its anti-cariogenic effects, the molecular pathways involved have remained unclear. In this study, we combined phenotypic and transcriptomic approaches to uncover the mechanism by which erythritol inhibits EPS synthesis. We found that erythritol treatment significantly reduces EPS production and biofilm density, and that these changes are accompanied by marked downregulation of the phosphotransferase system (PTS), particularly the celB gene. Functional validation through gene deletion demonstrated that loss of celB mimics the effects of erythritol, resulting in reduced bacterial growth, impaired biofilm formation and decreased EPS production. Our results establish celB as a key mediator of erythritol-induced biofilm inhibition and suggest that targeting carbohydrate transport systems could offer a novel approach to caries prevention.