Lactobacillus Plantarum 108 Inhibits Streptococcus mutans and Candida albicans Mixed-Species Biofilm Formation

Streptococcus mutansis the principal biofilm forming oral pathogen associated with dental caries. Studies have shown thatCandida albicans, a commensal oral fungus is capable of forming pathogenic mixed-species biofilms withS. mutans.The treatment of bacterial and fungal infections using conventional antimicrobial agents has become challenging due to the antimicrobial resistance of the biofilm mode of growth. The present study aimed to evaluate the efficacy of secretory components ofLactobacillus plantarum 108, a potentially promising probiotic strain, againstS. mutansandC. albicanssingle and mixed-species biofilms.L. plantarum 108supernatant inhibitedS. mutansandC. albicanssingle-species biofilms as shown by XTT reduction assay, crystal violet assay, and colony forming units counting. The probiotic supernatant significantly inhibited theS. mutans and C. albicansmixed-species biofilm formation. The pre-formed mixed-species biofilms were also successfully reduced. Confocal microscopy showed poorly developed biofilm architecture in the probiotic supernatant treated biofilms. Moreover, the expression ofS. mutansgenes associated with glucosyltransferase activity andC. albicanshyphal specific genes (HWP1, ALS1andALS3) were down-regulated in the presence of the probiotic supernatant. Altogether, the data demonstrated the capacity ofL. plantarum 108supernatant to inhibit theS. mutansandC. albicansmixed-species biofilms. Herein, we provide a new insight on the potential of probiotic-based strategies to prevent bacterial-fungal mixed-species biofilms associated with dental caries.