Effects of Consumption of Probiotic Yogurt on Salivary Streptococcus mutans, IL-1β and TNF-α Levels in Adults with Initial Stages of Dental Caries: a Randomized, Double‑Blind, Placebo‑Controlled Clinical Trial

Abstract Background Dental caries is one of the most common human diseases. The aim of the present study was to determine the effect of consumption of probiotic yogurt containing Bifidobacterium lactis Bb12 on salivary Streptococcus mutans (S. mutans), interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) levels in adults with initial stages of dental caries. Methods and Material: Sixty six 18–30 years old students with initial stages of dental caries were selected for this 2 weeks double blind randomized placebo controlled clinical trial and were randomly assigned into two groups: intervention (300g/d probiotic yogurt), and control (300 g/d conventional yogurt) groups. Unstimulated fasting saliva sample (2–3 ml) was collected pre and post-intervention for S. mutans bacteria counting and measurement of IL-1β and TNF-α cytokines levels. All Data were analyzed using SPSS. Results Salivary S. mutans and IL-1β changes were statistically signifcant in intervention group compared to their baseline and compared to the control group post intervention. Conclusion Consumption of probiotic yogurt containing B. lactis Bb12 may be beneficial for preventing of the progression of dental caries. Trial registration: This study was registered in Iran clinical trials: IRCT2014062518240N1.