Enterococcus faeciumWB2000 Inhibits Biofilm Formation by Oral Cariogenic Streptococci

This study investigated the inhibitory effect of probioticEnterococcus faeciumWB2000 on biofilm formation by cariogenic streptococci. The ability ofE. faeciumWB2000 and JCM5804 andEnterococcus faecalisJCM5803 to inhibit biofilm formation by seven laboratory oral streptococcal strains and 13 clinical mutans streptococcal strains was assayed. TheEnterococcalstrains inhibited biofilm formation in dual cultures with the mutans streptococcal strainsStreptococcus mutansXc andStreptococcus sobrinusJCM5176 (P<0.05), but not with the noncariogenic streptococcal strains.Enterococcus faeciumWB2000 inhibited biofilm formation by 90.0% (9/10) of the clinicalS. mutansstrains and 100% (3/3) of the clinicalS. sobrinusstrains. After culturing, the pH did not differ between single and dual cultures. The viable counts of floating mutans streptococci were lower in dual cultures withE. faeciumWB2000 than in single cultures.Enterococcus faeciumWB2000 acted as a probiotic bacterial inhibitor of cariogenic streptococcal biofilm formation.