The microbial abundance dynamics of the paediatric oral cavity before and after sleep

Objective: Microhabitats in the oral cavity differ in microbial taxonomy. However, abundance variations of bacterial and viral communities within these microhabitats are not fully understood. Aims and Hypothesis: To assess the spatial distribution and dynamics of the microbial abundances within 6 microhabitats of the oral cavity before and after sleep. We hypothesise that the abundance distributions of these microbial communities will differ among oral sites. Methods: Using flow cytometry, bacterial and virus-like particle (VLP) abundances were enumerated for 6 oral microhabitats before and after sleep in 10 healthy paediatric sleepers. Results: Bacterial counts ranged from 7.2 +/- 2.8 x 10(5) at the palate before sleep to 1.3 +/- 0.2 x 10(8) at the back of the tongue after sleep, a difference of 187 times. VLPs ranged from 1.9 +/- 1.0 x 10(6) at the palate before sleep to 9.2 +/- 5.0 x 10(7) at the back of the tongue after sleep, a difference of 48 times. Conclusion: The oral cavity is a dynamic numerically heterogeneous environment where microbial communities can increase by a count of 100 million during sleep. Quantification of the paediatric oral microbiome complements taxonomic diversity information to show how biomass varies and shifts in space and time.