TL;DR blacks have different microbes in their mouths than whites.
Title:
Deep Sequencing Identifies Ethnicity-Specific Bacterial Signatures in the Oral Microbiome
Abstract:
Oral infections have a strong ethnic predilection; suggesting that ethnicity is a critical determinant of oral microbial colonization. Dental plaque and saliva samples from 192 subjects belonging to four major ethnicities in the United States were analyzed using terminal restriction fragment length polymorphism (t-RFLP) and 16S pyrosequencing. Ethnicity-specific clustering of microbial communities was apparent in saliva and subgingival biofilms, and a machine-learning classifier was capable of identifying an individual’s ethnicity from subgingival microbial signatures. The classifier identified African Americans with a 100% sensitivity and 74% specificity and Caucasians with a 50% sensitivity and 91% specificity. The data demonstrates a significant association between ethnic affiliation and the composition of the oral microbiome; to the extent that these microbial signatures appear to be capable of discriminating between ethnicities.
Discussion: I wonder how this one would be spun by race-denialists into a "social construct" or to it being the results of "oppression" - even when they live among us and eat the same goyslop, their bodies are so different that we can't host the same bacteria as each other!
As an aside, I wonder if this also explains the prevalence of bacterial vaginosis among black females ...at least, maybe partially explains it - the other explanation being promiscuity and poor hygiene.