Fig. 1

Oral microbiota distribution according to their metabolic and biochemical characteristics. Although there is an overlap of all species in all oral sites, species of Streptococcus spp., Gemella spp., Granulicatella spp., Neisseria spp., and Prevotella spp. are found more frequently in the saliva. In other hand, it appears that bacteria that are located on the hard palate are not primarily the same as those present on the tongue. Rothia spp. typically colonize the tongue or tooth surfaces, Simonsieur spp. colonizes only the hard palate, S. salivarius mainly colonizes the tongue, and Treponema spp. is typically restricted to the gingival and subgingival tissue