The Effect of Dental Probiotic Use on the Inhibition of Streptococcus Mutans: A Clinical Study

Brief Background: Streptococcus mutans (S.mutans) is the pioneering pathogenic bacteria responsible for the initiation of dental caries. Controlling S.mutans activity using dental probiotics may have an impact on caries incidence and oral health in general. Objective: To evaluate the effects of commercially available dental probiotics (PRO-Dental, Hyperbiotics Inc.) usage for 60 days in a row on the cariogenic bacterium S.mutans in high caries risk patients with high or low S.mutans counts at baseline and 30 days after the discontinuation of use. Methodology: A total of 30 consenting adult patients with high caries risk (according to NSU CAMBRA protocol) without any complex medical history or recent antibiotic usage were recruited after IRB approval. Standardized oral hygiene instructions and oral hygiene care kit were given to all patients after a periodontal cleaning. Baseline saliva sampling was performed. Patients were given 60 day supply of dental probiotic tablets containing live bacteria of S.salivarius K12, S.salivarius M18, L.reuteri, L.paracasei, and zinc (PRO-Dental) following the manufacturer’s instructions (1tablet/day, before bed). After 30 days, patients were recalled for saliva sampling, and they were instructed to continue using probiotics. Upon completion of probiotic dose (60-days), the subjects were recalled for saliva sampling. After 30 days of probiotics discontinuation, patients were recalled for the last saliva collection. Saliva samples were collected at each time by chewing a paraffin wax to stimulate salivation (1ml). The samples were then diluted to 100, 1000, and 10,000 times in phosphate-buffered saline. Resulting serially-diluted bacterial suspensions were inoculated to a mitis-salivarius-bacitracin-potassium-tellurite agar plate and incubated in an anaerobic jar at 37°C for 48h. S.mutans colonies observed on the agar plate were counted using colony-forming units (CFU) per ml of stimulated saliva. The results were statistically analyzed using Pairwise comparisons with Bonferroni adjustment of margins was used to look for specific differences across time periods, and Poisson distribution was conducted to account for the data measurement scale. Statistical significance was found at p\u3c0.05. Results: Across all cell counts of 100, 1000, 10000, and baseline, significant differences were found across time (p \u3c 0.05). S.mutans count decreased by %48.5 after 30 days and by %83.9 after 60 days of probiotic usage. After 30 days of probiotic discontinuation. S.mutans counts got increased by %14.4. The continued suppression of the S.mutans for 30 days was statistically significant (p \u3c 0.05), it reduced by %69.5 from the baseline. Compliance was 100%, with no adverse events. Conclusion: The daily administration of dental probiotics for 60 days sufficiently suppressed the level of oral S.mutans and suppression continued for 30 more days. Further long-term research is needed to evaluate the sustainability of probiotics on the continued suppression of this cariogenic bacterium