Analysis of the microbial community diversity in various regions of the healthy oral cavity

Background: To investigate the differences in microbial colony distribution in different parts of a healthy oral cavity. Methods: We assessed four sites and two methods for sampling the bacterial community of healthy individuals, and identified the colonization of bacteria on the tooth surface and buccal mucosa. Specifically, we analyzed buccal mucosa (n=10) and tooth surface (n=20) samples from healthy individuals using 16S rDNA gene sequencing. Additionally, we detected bacterial signals in healthy individuals through fluorescence in situ hybridization (FISH), which targeted the bacterial 16S rDNA gene. Results : The results indicate that there are no significant differences between the buccal mucosa and tooth surfaces in normal individuals. However, when detecting disease-associated pathogens such as Enterococcus faecalis and Porphyromonas gingivalis , it is important to use different methods and specific sampling sites. The statistics suggest that although there were no significant differences in colony composition, there were differences in the abundance and distribution of colonies on the dental and buccal mucosal surfaces. Compared to right tooth sampling with a curette, the swab sampling group had higher levels of Firmicutes , while Fusobacteria and Bacteroidetes were more prevalent in the curette tissues. Conclusions: These data provide a different perspective for future investigation on healthy people’s bacterial distribution. In normal individuals, there is no difference in the bacterial composition of the oral buccal mucosa and the dental surface, differing only in abundance. Thus, the buccal mucosa can ask as a substitute for the teeth in epidemiological investigations exploring the bacterial composition of the oral cavity.