Inhibition of Cariogenic Biofilm Formation by Commercially Available Honey

Abstract

　Dental caries is an oral disease in which the hard tissues of the teeth are affected by acids produced by oral bacteria. The onset of dental caries is associated with biofilm formation by Streptococcus mutans, a commensal oral bacterium. Honey has been reported to have bactericidal effect on S. mutans ; however, information regarding its anti-biofilm properties is lacking. In this study, we investigated the growth and biofilm inhibitory effects of six commercial honeys on S. mutans, and found that all six honeys had almost the same growth inhibitory effect, while the biofilm inhibitory effect differed greatly among the samples. The fractions of ＞ 10 KDa obtained from samples A and B, which showed high biofilm inhibition, did not inhibit bacterial growth while inhibiting the formation of the biofilm. The level of α-glucosidase was higher in samples A and B than that in other honey samples, and the inhibitory effect on biofilm formation was correlated with the activity of this enzyme. Commercially available yeast-derived α-glucosidase had the same inhibitory effect on biofilm formation as that shown by the honey samples. This study is the first to describe the inhibitory effect of honey on biofilm formation. Honey may be beneficial as an anti-caries food material.