It is intended to provide an oral flora-improving agent capableof forming a favorable flora in the oral cavity and a food or adrink for improving the oral flora. An oral flora-improving agentcontaining as an active ingredient a ganglioside and a food, a drink,or a feed for improving the oral flora containing the gangliosideexhibit an antibacterial effect on harmful bacteria in the oralcavity, which are undesirable from the viewpoint of decay and diseasessuch as periodontal disease, and a growth-improving effect on usefulbacteria to be preserved in the oral cavity. Further, the gangliosideis efficaciously used as an active ingredient in an antibacterialagent or an antibacterial drink, food, or feed, a growth promoter,or a food, a drink, or a feed for promoting growth.
