FIG 2.

Approaches to studying the dynamics of the oral microbiota during health and disease. Microscopy and sequencing-based community profiling are powerful approaches that can be leveraged for spatiotemporal studies of oral microbial ecology to further understand the relationship of the oral microbiota with health and disease. Confocal scanning microscopy of labeled strains reveals changes in micron-scale biogeography and the corresponding changes in microbial interactions. Community profiling, for instance, using metagenomics and metatranscriptomics, shows changes in the composition and functional activities of samples across space or time. These methods are important in both top-down and bottom-up approaches. For example, top-down approaches could sample the oral biofilm over time after a professional cleaning (60). For bottom-up approaches, emergent spatiotemporal dynamics can be observed using a small number of cells directly removed from oral specimens with micromanipulators or using communities constructed from pure cultures of strains (61).