Arginine Metabolism and the Oral Microbiome: Ecological Pathways Linking Nutrition to Periodontal Health

Abstract Periodontal disease is a complex inflammatory disorder that arises from imbalanced interactions between oral microorganisms and the host immune response. Recent evidence indicates that the amino acid L-arginine exerts significant ecological influences within the oral microbiome. Certain commensal bacteria metabolize arginine via the arginine deiminase system (ADS), producing ammonia that counteracts acid accumulation and stabilizes plaque pH. This buffering action promotes the persistence of beneficial microbial species while restricting acid-tolerant pathogens. Experimental, animal, and human studies have shown that arginine especially when incorporated into dentifrices can enhance ADS activity, reduce biofilm biomass, and potentially modulate inflammation. However, only limited research has directly examined its effects on periodontal outcomes such as probing depth, clinical attachment level, and bleeding indices. This review synthesizes current findings on the biochemical and ecological mechanisms by which arginine functions as a prebiotic substrate, connecting nutrition, microbial dynamics, and periodontal health, and highlights emerging directions for arginine-centered preventive strategies.