Background: The aim of the current study is to compare the prevalence of commensal bacteria, with beneficial properties, for healthy and diseased individuals and additionally to examine the inhibitory effect of some commercial dietary probiotics on periodontopathogens, comparing this inhibitory effect to that of orally derived beneficial bacteria.
Methods: Subgingival plaque samples from 35 patients (healthy and periodontitis patients) were analyzed. Growth inhibition of the periodontal pathogens Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans was examined using the agar overlay technique and agar well diffusion method. The quantification of the inhibitory effect was checked with the agar well diffusion method.
Results: Using the agar overlay technique, the prevalence of strains antagonistic toward P. gingivalis, A. actinomycetemcomitans, and F. nucleatum was found to be higher in healthy individuals than in individuals with periodontitis, but this could not be validated by the agar well diffusion assay. Compared with the antagonistic activity of the isolated strains, the probiotic strains overall showed a stronger inhibition of the periodontal pathogens.
Conclusion: It was shown that some oral bacteria can cause antagonism toward periodontopathogens, and these observations underline the therapeutic potential of applications that stimulate oral health by the application of beneficial effector strains.