Potential effects of a multistrain probiotic-kefir on salivary Streptococcus mutans and Lactobacillus spp.

Abstract

It has recently been documented that various probiotic formulations have beneficial effects in reducing caries risk as well as promoting human health. The aim of the present study was to examine the efficacy of short-term consumption of a multistrain probiotic-kefir on salivary counts of Streptococcus mutans and Lactobacillus spp. in young adults. In total, 104 subjects aged 20-27 years were included in the study. The salivary flow rate, buffer capacity, salivary mutans streptococci and lactobacilli counts were detected in each subject after a 3-week washout period using chair-side kits at baseline. Subjects were randomly assigned into three groups: Group I consumed 100 mL kefir per day (n = 35); Group II consumed 2 ± 100 mL kefir per day (n = 35); and Group III consumed 100 mL milk (n = 34). A questionnaire investigating the oral and dietary habits of the subjects was also filled out by each subject. After 3 weeks of consumption of the experimental materials, salivary mutans streptococci and lactobacilli counts were reevaluated. Statistically significant reductions were observed in both salivary mutans streptococci and lactobacilli in Group II compared to the baseline (P = 0.001 and P = 0.01, respectively). Short-term consumption of kefir might reduce high levels of salivary mutans streptococci and lactobacilli.