Provided are a use of D-galactose in inhibition of quorum sensing and/or in prevention and/or treatment of oral bacterial diseases； in particular, a composition for inhibiting quorum sensing and a composition for preventing and/or treating oral bacterial diseases, the composition comprising D-galactose, and a method of inhibiting quorum sensing and a method of preventing and/or treating oral bacterial diseases, the method comprising administering D-galactose.
