The role of glutathione metabolism in cariogenic bacterial growth and caries in Korean children

The involvement of antioxidants in oral diseases suggests that salivary glutathione level may be associated with cariogenic bacteria and dental caries. The aim of this study was to determine the association of salivary glutathione with dental caries and cariogenic bacteria. This is a cross-sectional oral health survey of 257 children aged 6–14 years. Total glutathione, reduced glutathione (GSH) and oxidised glutathione (GSSG) levels were measured. Salivary mutans streptococci (MS) and Lactobacilli (LB) were measured using Dentocult MS and Dentocult LB kits. The dental caries status was examined. Analysis of covariance (ANCOVA) and a linear regression model were used to evaluate the association among glutathione metabolites, cariogenic bacteria and dental caries status. The salivary GSH level of the children was found to be significantly increased according to the salivary LB level and DMFT (decayed, missing, filled teeth) (p = 0.034 for salivary LB level; p = 0.018 for DMFT). The glutathione metabolite levels were significantly higher in the decayed tooth (DT) group (p < 0.001 for total glutathione and GSH; p = 0.012 for GSSG). The GSH level showed a significant linear relationship with the salivary LB level (p = 0.016), DMFT score (p = 0.005) and DT score (p = 0.010). Total glutathione and GSSG levels exhibited a significant linear relationship with DT (p = 0.021). This result indicates that the GSH level in saliva increased significantly in children according to the salivary LB level and the presence of dental caries. GSH may be a biomarker for cariogenic bacteria and dental caries.