Abstract
OBJECTIVE: To investigate the effects of a probiotic drink containing Lactobacillus casei strain Shirota on dental plaque microbiota. METHODS: Caries-free young adults were administered a probiotic drink containing L. casei Shirota (Yakult) three times on day 1, then once daily for 28 days. Dental plaque samples were collected and analysed by 16S rRNA sequencing before (day 1), during (day 2), and one day following intervention (day 30). RESULTS: Out of samples from 10 included participants, 256 814 sequences passed through quality control, clustered into 170–234 different ‘species-level’ phylotypes. Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria were the most abundant phyla. Dental plaque microbiota composition significantly changed at different taxonomic levels following probiotic consumption. At genus level, the relative abundance of Veillonella and Kingella increased significantly following intervention, while that of Leptotrichia reduced significantly during intervention, but recovered to baseline level at day 30. Alpha diversity and overall structure of the dental plaque microbiota was not significantly impacted by the probiotic. CONCLUSION: Yakult intake changed the abundance of some bacteria related to caries, suggesting that the change of composition may be beneficial to oral health, while the overall microbiota structure remained unaffected.