Composition of microbial oral biofilms during maturation in young healthy adults

Abstract

In the present study we aimed to analyze the bacterial community structure of oral biofilms at different maturation stages in young healthy adults. Oral biofilms established on membrane filters were collected from 32 human subjects after 5 different maturation intervals (1, 3, 5, 9 and 14 days) and the respective phylogenetic diversity was analyzed by 16S rDNA amplicon sequencing. Our analyses revealed highly diverse entire colonization profiles, spread into 8 phyla/candidate divisions and in 15 different bacterial classes. A large inter-individual difference in the subjects' microbiota was observed, comprising 35% of the total variance, but lacking conspicuous general temporal trends in both alpha and beta diversity. We further obtained strong evidence that subjects can be categorized into three clusters based on three differently occurring and mutually exclusive species clusters.

Figure 1. Mean bacterial composition of oral biofilms over time in individual subjects.

Bacterial communities of oral biofilms in 32 different human subjects were analyzed by 16S rDNA amplicon deep sequencing (V1–V2 region). Taxa (mean relative abundance across subjects ≥1%) are shown at class and genus levels.

Figure 2. Species and subject clusters.

Combined consensus clustering and ordination (PCA) of robust species and human subjects. (A) First (PC1) and second (PC2) axis and (B) first (PC1) and third axis (PC3) of the ordination space of individual subject samples are shown. Species data points (small spheres) are projected into the ordination space as weighted averages and grouped into three clusters according to species consensus clustering: “Prevotella cluster” (magenta), “Streptococcus cluster” (orange), “Proteobacteria cluster” (green). Large spheres represent the centroids of individual sample points for each human subject, color-coded according to the result of subject consensus clustering. (C) Relative species abundances in subject clusters. Color coding of species clusters is analogous to (A) and (B).