Washington: A new study has found that oral bacteria, particularly those present below the gums, are as unique as a fingerprint when it comes to identifying a person's ethnicity.
Scientists collected samples of bacteria from the saliva, tooth surfaces and under the gums and identified a total of almost 400 different species of microbes in the mouths of 100 study participants belonging to four ethnic affiliations: non-Hispanic blacks, whites, Chinese and Latinos.
Only 2 percent of bacterial species were present in all individuals - but in different concentrations according to ethnicity - and 8 percent were detected in 90 percent of the participants.
Beyond that, researchers found that each ethnic group in the study was represented by a "signature" of shared microbial communities.
Purnima Kumar , associate professor of periodontology at the Ohio State University and senior author of the study, said that no two people were exactly alike and that's truly a fingerprint.
Kumar used a DNA deep sequencing methodology to obtain an unprecedented in-depth view of these microbial communities in their natural setting.
When the scientists trained a machine to classify each assortment of microbes from under the gums according to ethnicity, a given bacterial community predicted an individual's ethnicity with 62 percent accuracy.
The classifier identified African Americans according to their microbial signature correctly 100 percent of the time.
"The most important point of this paper is discovering that ethnicity-specific oral microbial communities may predispose individuals to future disease," Kumar said.
The research is published in the journal PLOS ONE.