No abstract

Saliva is a vital mediator in the oral cavity. The dysbiosis of free bacteria in saliva might be related to the onset, development, prognosis, and recurrence of periodontal diseases, but this potential relationship is still unclear. The objective of this study was to investigate the potential roles of the free salivary microbiome in different periodontal statuses, their reaction to nonsurgical periodontal therapy, and differences between diseased individuals after treatment and healthy persons. We recruited 15 healthy individuals, 15 individuals with gingivitis, and 15 individuals with stage I/II generalized periodontitis. A total of 90 unstimulated whole saliva samples were collected and sequenced using full-length bacterial 16S rRNA gene sequencing. We found that as the severity of disease increased, from healthy to gingivitis and periodontitis, the degree of dysbiosis also increased. A higher abundance of Prevotella intermedia and Catonella morbi and a lower abundance of Porphyromonas pasteri, Prevotella nanceiensis, and Haemophilus parainfluenzae might be biomarkers of periodontitis, with an area under curve (AUC) reaching 0.9733. When patients received supragingival scaling, there were more pathogens related to recolonization in the saliva of periodontitis patients than in healthy persons. Even after effective nonsurgical periodontal therapy, individuals with periodontitis displayed a more dysbiotic and pathogenic microbial community in their saliva than healthy individuals. Therefore, the gradual transition in the entire salivary microbial community from healthy to diseased includes a gradual shift to dysbiosis. Free salivary pathogens might play an important role in the recolonization of bacteria as well as the prognosis and recurrence of periodontal diseases.

Objective To explore the changes of peptidome profiles of saliva, serum, and gingival crevicular fluid (GCF) before and after non‐surgical periodontal treatment in patients with generalized periodontitis (stage I/II). Subjects and methods Saliva, serum, and GCF samples were collected from 17 patients at baseline (T0), one week after ultrasonic supragingival scaling (T1) and eight weeks after subgingival scaling and root planning (T2). Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was carried out to detect changes in peptidomic profiles. Then, nano‐liquid chromatography‐electrospray ionization‐tandem mass spectrometry (nano‐LC/ESI‐MS/MS) was performed to identify potential peptide biomarkers. Results Most of the peptides from the patients exhibited a decreasing trend from the time point of pretreatment to that of post‐treatment. Cluster analysis and scatter plots using these peptides indicated that salivary peptidome has an acceptable capability of reflecting the status of stage I/II generalized periodontitis. Seven of these peptides were successfully identified as α‐1‐antitrypsin, immunoglobulin κ variable 4‐1, haptoglobin, and immunoglobulin heavy constant γ2. Conclusions Certain peptides in saliva, serum, and GCF were down‐regulated after non‐surgical periodontal treatment, demonstrating the application prospects of saliva in monitoring and surveillance of periodontal diseases in both clinical settings and communities.