Exploring Intra-individual Oral Microbiome diversity and Streptococcal Colonisation Patterns

The aim of this study was to characterise how microbial communities vary across the different hard and soft tissue sites of the healthy oral cavity, an environment characterised by distinct ecological niches that remain poorly understood. Using 16S rRNA gene sequencing as the main approach, we examined variation in overall bacterial composition, diversity, and community structure across saliva, tongue, buccal mucosa, and dental surfaces, while strain-level fingerprinting of Streptococcus isolates provided supporting information on clonal patterns within individuals. By showing apparent differences in microbial communities between sites, alongside evidence that some Streptococcus clones are shared across habitats, this work offers an essential foundation for understanding how microbial communities coexist and interact within the healthy oral environment.