Lactobacillus paracasei ET-22 Suppresses Dental Caries

Dental caries is a multifactorial biofilm disease that is influenced by dietary habits and microbiota. Among the various pathogens involved in the caries process, Streptococcus mutans (S. mutans) is the most extensively studied. The use of probiotics to promote oral health has gained considerable attention. Lactobacillus paracasei (L. paracasei) strains have been reported to modulate the gut microbiota and enhance host resistance to disease. However, researches on the preventive effects and functional mechanisms of L. paracasei on dental caries are limited. In this study, the preventive effects of L. paracasei ET-22 on dental caries in mice were checked. Meanwhile, the functional mechanism of L. paracei ET-22 was further investigated. Results showed that the supplementation of L. paracei ET-22 in drinking water significantly improved the caries scoring of mice. The microbiota of dental plaques revealed that both the live and heat-killed L. paracei ET-22 similarly regulated the microbial structure in plaques biofilms. Functional prediction of PICRUSt showed that the supplementation of live and heat-killed L. paracei ET-22 may inhibit the biofilm formation. By the in vitro trials, the live and heat-killed L. paracei ET-22 indeed inhibited the formation of S. mutans biofilms and EPS productions of biofilms. Theses evidences suggest that L. paracei ET-22 can inhibit dental caries by regulating microbiota of dental plaques and inhibiting biofilm formation, which may be partly mediated by the body components of L. paracei ET-22.