The present invention provides an oral care composition comprising a carboxylic acid of the formula: wherein: R1 is H, or is a substituted or unsubstituted alkyl group； and R2 is H, OH, or NH2； or wherein the carboxylic acid of formula I is fumaric acid or N-acetylneuraminic acid； for use in: (a) selectively promoting, in an oral cavity: growth, metabolic activity or colonization of bacteria that have beneficial effects on oral health, relative to growth, metabolic activity or colonization of pathogenic oral bacteria； (b) selectively promoting, in an oral cavity, biofilm formation by bacteria that have beneficial effects on oral health, relative to biofilm formation by pathogenic oral bacteria； or (c) maintaining and/or re-establishing a healthy oral microflora.本發明提供一種包含式I之羧酸的口腔保健組成物：其中：R1是H，或經取代或未經取代的烷基；且R2是H、OH或NH2；或其中該式I羧酸是反丁烯二酸或N-乙醯神經胺酸；其用途在於：(a)相對於病原性口腔細菌的生長、代謝活性或移生，選擇性的在口腔中促進對口腔健康有良性影響之細菌的生長、代謝活性或移生；(b)相對於病原性口腔細菌的生物膜形成，選擇性的在口腔中促進對口腔健康有良性影響的細菌之生物膜形成；或(c)維持和或重建健康的口腔微生物相。
