Just appearing this month in PloS Biol [see attached 2nd article], this article is consistent with what our GEITP pages have been describing the last several days. The human gut microbiome is known to vary extensively between individuals, and this variability is frequently associated with diet, age, sex, and body mass index (BMI) — as well as diseases presenting as health disparities. The overlapping risk factors and burden of many chronic diseases disproportionally affect ethnic minorities in the US. Recent evidence is in agreement with the hypothesis that ethnicity is correlated with variation in microbial abundance, specifically in the microbiomes of the gut, oral cavity, and vagina.
To varying degrees, ethnicity can capture many facets of biological variation — including social, economic, and cultural variation — as well as aspects of human genetic variation and biogeographical ancestry. Ethnicity also serves as a proxy to characterize health disparity incidence in the US and, whereas factors such as genetic admixture create ambiguity of modern ethnic identity, self-declared ethnicity has proven a useful proxy for genetic and socioeconomic variation in population-scale analyses.
By examining associations between ethnicity and differences in two US-based gut microbiota data sets that included 1,673 individuals, authors found 12 microbial genera and families that reproducibly vary by ethnicity. A majority of these microbial taxa — (including the most heritable bacterial family Christensenellaceae) — overlap with genetically associated taxa and form co-occurring clusters linked by similar fermentative and methanogenic metabolic processes. These results demonstrate recurrent associations between specific taxa in the gut microbiota and ethnicity, providing hypotheses for examining specific members of the gut microbiome as mediators of health disparities.
PloS Biol Dec 2o18; 16: e2006842