Composition of Salivary Microbiota May Forecast the Severity of Periodontal Disease

In a study published in the American Journal of Microbiology, researchers sought to investigate the compositional fluctuations in the salivary microbiota according to the severity of periodontal disease. The researchers also aimed to confirm whether the circulation of particular bacterial species in saliva can differentiate the severity of the periodontal disease.

The authors wrote, “The objective of this study was to identify specific bacterial species to distinguish the severity of periodontal disease by analyzing the salivary microbiota using 16S rRNA gene sequencing and quantitative real-time PCR (qPCR).”

For this study, researchers obtained 72 saliva samples via the mouth rinse method to get more bacteria by washing away ones attached to oral surfaces, including teeth, through gargling.  The 72 samples were collected from four groups comprised of 8 periodontally healthy controls, 16 patients with gingivitis, 19 patients with moderate periodontitis, and 29 patients with severe periodontitis.

Among study participants, there were no noteworthy variances with regard to average ages, number of teeth, or number of dental caries. However, among the four groups, gender and smoking status showed noteworthy variances. Within the gingivitis group, all 16 cases were females; of the 19 subjects with moderate periodontitis, 10 were female, and in the severe periodontitis group, 12 were female.  However, males accounted for 17 of the 29 cases of severe periodontitis, and males also represented a greater percentage of smokers in all four groups.  

Results revealed that 29 species, including Porphyromonas gingivalis, augmented as the severity of the disease expanded; however, 6 species, including Rothia denticola, diminished.

The authors wrote, “The relative abundances of P. gingivalis, Tannerella forsythia, Filifactor alocis, and Prevotella intermedia determined by qPCR were significantly different among the groups. The three bacterial species P. gingivalis, T. forsythia, and F. alocis were positively correlated with the sum of the full-mouth probing depth and were moderately accurate at distinguishing the severity of periodontal disease.”

The authors also indicated that as the severity of periodontal disease intensified, the phyla Bacteroidetes, Fusobacteria, and Spirochaetes were meaningfully more plentiful, while the phylum Actinobacteria was considerably less ample.

Based on their findings, the authors concluded that according to the severity of periodontitis, the salivary microbiota demonstrated gradual compositional alterations, and the levels of P. gingivalis, T. forsythia, and F. alocis as biomarkers in mouth rinse saliva had the capacity to recognize the severity of the periodontal disease.

Lastly, the authors indicated that large-scale studies are required to ascertain if these three bacterial species can recognize all stages of the disease and to establish the optimal standards for distinguishing the severity of periodontal disease.

Reference:

Ji S, Kook JK, Park SN, Lim YK, Choi GH, Jung JS. Characteristics of the Salivary Microbiota in Periodontal Diseases and Potential Roles of Individual Bacterial Species To Predict the Severity of Periodontal Disease. Microbiol Spectr. 2023 Jun 15;11(3):e0432722. doi: 10.1128/spectrum.04327-22