Abstract

Microbiome science asserts humans are made up of more microbial cells and genes than human ones, and that each person harbors their own unique microbial population. Human microbiome studies gesture toward the post-racial aspirations of personalized medicine—characterizing states of human health and illness microbially. By viewing humans as “supraorganisms” made up of millions of microbial partners, some microbiome science seems to disrupt binding historical categories often grounded in racist biology, allowing interspeciality to supersede race. But inevitably, unexamined categories of race and ethnicity surface in a myriad of studies on microbiota. This paper approaches race as a ghost variable across microbiome research and asks, what is race doing in studies of the microbiome? Why is it there, and how is it functioning? I examine this research to argue that social scientists must work with biological scientists to help put microbial differences into perspective—to investigate how microbiomes and race are entangled embodiments of the social, environmental, and biological. Ultimately, transdisciplinary collaboration is required to address racial health disparities in microbiome research without reifying race as a straightforward biological or social designation.