Nutritional stimulation of commensal oral bacteria suppresses pathogens: the prebiotic concept

To identify potential oral prebiotics that selectively stimulate commensal, albeit beneficial bacteria of the resident oral microbial community while suppressing the growth of pathogenic bacteria.

Using Phenotype MicroArrays as a high-throughput method, the change in respiratory activity of 16 oral bacteria in response to 742 nutritional compounds was screened. Most promising prebiotic compounds were selected and applied in single species growth and biofilm formation assays, as well as dual species (beneficial-pathogen) competition assays.

Increased respiratory activity could not always be related to an increase in growth or biofilm formation. Six compounds were used in dual species competition assays to directly monitor if selective nutritional stimulation of the beneficial bacterium results in the suppression of the pathogenic bacterium. Two compounds, beta-methyl-d-galactoside and N-acetyl-d-mannosamine, could be identified as potential oral prebiotic compounds, triggering selectively beneficial oral bacteria throughout the experiments and shifting dual species biofilm communities towards a beneficial dominating composition at in vitro level.

Our observations support the hypothesis that nutritional stimulation of beneficial bacteria by prebiotics could be used to restore the microbial balance in the oral cavity and by this promote oral health.