Evaluation of the effect of Kidi Lact probiotic product on streptococcus mutans in saliva in a group of 8-12-year-old children

Previous studies have shown that lactobacillus presented in food products affects oral ecology. In this study, we decided to show the effect of periodic use of Kidi Lact, a product containing probiotic bacteria which is recommended for improvement of gastrointestinal (GI) function in babies and children by physicians, on level of streptococcus mutans (S. mutans) in saliva among children between 8-12 years old. There are no previous studies in this relation. This randomized crossover double-blind study was conducted on 30 healthy children between the age of 8-12 years. It included four steps. In the first step, children randomly were divided in two groups; in the step two, one of them used 1gr Kidi Lact every day and other group used placebo every day during two weeks, randomly. In the third step, children used none of them for one month, and finally in the step four, those who used Kidi Lact at step two, used placebo and other group vice versa. At the end of each step, samples of the children saliva was prepared and then, the number of S. mutans in the non-stimulated saliva samples was measured with microbial culture method. SPSS statistical software was used for data analysis. S. mutans reduction in saliva after using Kidi Lact was statistically significant (P < 0.001), but it showed no significant reduction after using placebo (P = 0.100). The amount of S. mutans in the two groups had no significant difference before using Kidi Lact and placebo (P = 0.406). Amount of S. mutans in the groups after using placebo and Kidi Lact was significant (P < 0.001). According to the present study, periodic use of Kidi Lact as a mouth wash has a strong effect on amount of S. mutans in saliva. So, physicians can be advised to tell their patients about rinsing of Kidi Lact before its swallowing.