Volatile sulfur compounds and oral microorganisms (VSCs)

Volatile sulfur compounds (VSCs) and oral microorganisms represent the primary chemical and biological components of oral malodor, commonly known as halitosis (StatPearls, 2023). The most significant VSCs include hydrogen sulfide, methyl mercaptan, and dimethyl sulfide, which are produced by the proteolytic activity of anaerobic Gram-negative bacteria residing on the tongue dorsum and in periodontal pockets (Moura et al., 2020). These microorganisms, such as Porphyromonas gingivalis, Treponema denticola, and Fusobacterium nucleatum, utilize enzymes like L-methionine gamma-lyase to degrade sulfur-containing amino acids (cysteine and methionine) into malodorous gases (PubMed, PMID: 22551350). Beyond their role in breath odor, VSCs are implicated in the pathogenesis of periodontal disease by increasing mucosal permeability and promoting the production of pro-inflammatory cytokines (Scully & Greenman, 2012). Therapeutic interventions typically target this system through the use of antimicrobial agents like chlorhexidine to reduce bacterial populations or metal ions, such as zinc, which chemically neutralize VSCs into non-volatile salts (NIH, 2022). While not a single molecular target, this interplay between the oral microbiome and its sulfurous metabolites is the central focus of pharmacological management for halitosis.

Other names

Oral malodor factorsHalitosis-associated microbiotaSulfur-producing oral bacteriaOral sulfur metabolism

Reduction of bacterial load via antimicrobial action and chemical neutralization of volatile sulfurous gases via metal ion chelation or oxidation.