Ethnicity specific microbial signatures in the oral microbiome

Abstract

Personalized medicine is based on the paradigm that definitions of health and disease vary significantly among individuals. Successful treatment of caries and periodontitis requires re-establishing healthy oral biofilms, and current treatment protocols assume that the composition of health-compatible biofilms is similar among all individuals. However, It has been established that susceptibility to these diseases varies among ethnicities suggesting that oral microbial communities differ between ethnicities. Therefore, we investigated if ethnicity contributes to the variations in the composition of health-compatible oral biofilms. Saliva, supragingival and subgingival plaque samples were collected from 192 adults of Caucasian, African-American, Hispanic, and Chinese ethnicities. All subjects reported no systemic disease, pregnancy, and recent or prophylactic antibiotic use. Terminal restriction fragment length polymorphism (t-RFLP) and 16s pyrotag sequencing were used for community and bacterial level characterizations. Microbial profiles were compared between ethnicities using Non-metric Multidimensional scaling and ANOVA. Random Forest Machine Learning Classifier was used to examine the efficacy of oral microbial signatures as predictors of ethnicity. Only subgingival microbial communities demonstrated significant clustering of t-RFLP patterns based on ethnicity. Although eight species were detected in all 100 individuals, microbial profiles that were unique to each ethnicity were identified. Further, African Americans demonstrated a significantly lower diversity and equitability when compared to the other ethnicities. The subgingival microbial fingerprint was capable of identifying an individual’s ethnicity with 62% accuracy, 58% sensitivity and 86% specificity. The fingerprint was best able to identify African Americans with a 100% sensitivity and 74% specificity. The work presented here provides evidence for the existence of ethnicity-specific subgingival microbiomes that are characterized by differing bacterial lineages and varying diversities. Understanding that the microbial profiles of healthy subgingival biofilms are unique to different ethnicities will drive the development of personalized therapeutics and treatment plans. This research was supported by the Ohio State College of Dentistry CTOC T32 DE 0143220 training grant.