Objective  To analyze the salivary metabolic profile of patients with periodontitis through metabolomic techniques and to explore the metabolic patterns associated with periodontal diseases.

  Methods  Liquid chromatography/mass spectrometry (LC/MS) technique in conjunction with principal component analysis (PCA) analysis and orthogonal partial least squares identification (OPLS-DA) method was used to study the metabolomics of saliva samples from gingivitis patients, periodontitis patients, and healthy controls, with 10 samples for each group. We examined the correlation between migration in metabolic profile and the progression of periodontal diseases.

  Results  Saliva metabolite profiles of gingivitis and periodontitis patients was significantly different from those of the healthy controls. Significant differences were identified between the different groups for eight salivary metabolites, including arachidonic acid, tyramine, L-arginine, thymine, N-acetylgalactosamine sulfate, prostaglandin E2, L-phenylalanine, and 5-aminoimidazole-4-carboxamide-riboside (AICAR). In comparison with those of the health controls, the concentration of AICAR in patients with gingivitis and periodontitis was lower and the metabolic trend was down-regulated, while the other metabolites were up-regulated.

  Conclusion  Salivary metabolic profile changes along with the progression of periodontal diseases. Abnormal metabolism of the periodontal tissue and of pathogenic microorganisms related to periodontal diseases is one of the mechanisms involved in the pathogenesis, development and prognosis of periodontal diseases.