Inhibitory effects of polysaccharides on the cariogenic activities of Streptococcus mutans.

Many carbohydrates are involved in the biofilm formation and activities of glucosyltransferases (Gtfs) of Streptococcus mutans, and the effects of various disaccharides and polysaccharides were investigated in this study, including the hot water-extracted glucan fraction of the Lentinula edodes fruiting body (HWG). HWG was found to inhibit the initial adhesion of S. mutans to saliva-coated hydroxyapatite (sHA), and also laminarin to inhibit glucan synthesis by Gtfs. However, sucrose-dependent biofilm formation by S. mutans was not inhibited by these materials. Interestingly, dextran was found to have an inhibitory effect on the sucrose-dependent biofilm formation. The data suggest that the presence of such an edible glucan as dextran in daily foods would act to some degree on S. mutans for suppressing the cariogenic activity.