Evaluation of probiotic milk on salivary mutans streptococci count: an in vivo microbiological study

The objective of the present study was to investigate the effect of probiotic Lactobacillus casei Shirota on the values of mutans streptococci counts in saliva. 31 children were included in this double blinded study. Study design included 4 periods which consisted of a run in period, two intervention periods and a washout period. During the intervention periods children were either given probiotic milk or control milk for 10 days. Pre and post intervention salivary samples were subjected to microbiological evaluation. Then numbers of mutans streptococci were taken by identifying colony morphology. A statistically significant reduction of mutans streptococci colony count was noted in the probiotic group (p=.003). The reduction in children with higher levels of mutans streptococci (105) after intervention was 34% in the probiotic group. Daily consumption of milk containing probiotic bacteria can reduce the levels of mutans streptococci and may contribute to the prevention of dental caries.