Periodontal disease is common and here in the UK 10-15% of adults have chronic periodontal disease.  It is a multifactorial disease and subgingival bacteria play an important role in the pathogenesis of the disease. The aim of this study was to see if chronic periodontitis is associated with a characteristic bacterial saliva profile, and if such a profile might be dependent on smoking status.

From a group of 4402 adult patients from the Danish Health Examination Survey (DANHES) who had had an oral examination (including other studies of bacterial profiles of saliva associated with caries and different lifestyle) 600 samples were randomly selected as control cohort.  159 samples from individuals with chronic periodontitis were identified according to the following criteria: bleeding on probing on ≥25% of total sites + minimum two teeth with clinical attachment level ≥4 mm + minimum two teeth with probing depth ≥6 mm.

• 144 samples were excluded as they contained too little saliva for further analysis and 29 samples were excluded as they failed in a PCR quality control step.  A total of 586 samples remained  (139 in the periodontitis group and 447 in the control group). Samples were analysed using the Human Oral Microbe Identification Microarray (HOMIM).
• More males were seen in the periodontitis group (48.2%), as compared to 40.1% of the control cohort (ns, p = 0.09).
• More smokers were identified in the periodontitis group (24%), when com- pared to 7% of the participants in the control cohort (p < 0.0001).
• Eight bacterial taxa, including putative periodontal pathogens as Parvimonas micra and Filifactor alocis, and four bacterial clusters were identified statistically more frequently and at higher levels in samples from periodontitis patients than in samples from the control cohort. These differences were independent of the individuals’ smoking status.

The authors concluded

Within the limitations of the present design, this case–cohort study provides evidence that chronic periodontitis is associated with a characteristic bacterial profile of saliva that is significantly different from that observed in the general population. Future longitudinal studies are warranted to elucidate if measurement of the bacterial profile of saliva, a readily accessible biomaterial, can be used as a biomarker of periodontitis

Comment

This study is interesting although the authors highlight two issues that are a always raised with studies of this type and that is whether the saliva sampling method was appropriate and had an impact on the detection of the bacteria present and whether the detection method was appropriate to identify all the bacteria present.

Links

Belstrøm D, Fiehn NE, Nielsen CH, Kirkby N, Twetman S, Klepac-Ceraj V, Paster  BJ, Holmstrup P. Differences in bacterial saliva profile between periodontitis patients and a control cohort. J Clin Periodontol. 2013 Nov 6. doi: 10.1111/jcpe.12190. [Epub ahead of print] PubMed PMID: 24303924.