Differences in bacterial saliva profile between periodontitis patients and a control cohort

Periodontitis is a multifactorial disease in which subgingival bacteria play an important role in the pathogenesis of the disease. The objective of this study was to determine if periodontitis is associated with a characteristic salivary bacterial profile. This was accomplished by comparing the bacterial profile of saliva from subjects with chronic periodontitis with that of saliva from a control cohort.

Stimulated saliva samples from 139 chronic periodontitis patients and 447 samples from a control cohort were analysed using the Human Oral Microbe Identification Microarray (HOMIM). Frequency and levels (mean HOMIM-value) of around 300 bacterial taxa/clusters in samples were used as parameters for investigation. Differences at taxon/cluster values between groups were analysed using Mann-Whitney U-test with Benjamini-Hochberg correction for multiple comparisons. Principal component analysis was used to visualize bacterial community profiles obtained by the HOMIM.

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.

Periodontitis is associated with a characteristic bacterial profile of saliva different from that of a control cohort.