Aim: This study aims to study the effect of short-term consumption of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 on salivary Streptococcus mutans count in high caries risk individuals.
Materials and methods: A double-blind randomized control trial was conducted, and 70 high caries risk individuals with a salivary S. mutans count of more than 106 CFU/ml of saliva were followed for 4 weeks. Participants ingested 100 g yogurt containing L. acidophilus La5 and Bifidobacterium lactis Bb12 or yogurt without the two probiotic bacteria once daily at the end of meals for initial 2 weeks. Salivary S. mutans were enumerated in the laboratory by selective culture media.
Results: A statistically significant reduction (P < 0.05) of salivary S. mutans was recorded after probiotic yogurt consumption with minimal residual effect, which was in contrast to the controls.
Conclusion: L. acidophilus La5 and Bifidobacterium lactis Bb12 present in the yogurt were effective in reducing the S. mutans levels in saliva.
Keywords: Bifidobacteria; Streptococcus mutans; caries prevention; lactobacilli; probiotics.