Paper short abstract:

I suggest some ways that evidence about the presence or absence of microbes in bodies might enrich critical analysis of medical subjectivity.

Paper long abstract:

Numerical evidence is central to the everyday operations of biomedicine. As scholars have shown, "target" quantities, from CD4 to cholesterol to body mass, are not just powerful indicators of well-being. They are also powerful tools of governance. By calculating these numbers, people "count themselves" as parts of populations at risk.

Attention to the role of microbes in regulating human health might alter this understanding of medical subjectivity. The human microbiome—the population of bacteria, viruses, fungi, and other creatures that live in and around the human body—is frequently described as a population of indeterminate "millions." Research in animals with microbial populations of "zero" has helped show how microbes operate symbiotically with their hosts, aiding in digestion, immunity, and even mood stabilization. Some experts are starting to advocate maintenance of a diversity of species, rather than adherence to strict numerical targets, as a pathway to good health.

The search for historical and contemporary evidence of the benefits of "bodily biodiversity" has made a set of bodies formerly marginal to biomedicine—namely, those of ancient and so-called "primitive" people—newly relevant. Drawing a comparison with work in historical ecology and environmental anthropology, I suggest that attention to how biodiversity has been evidenced (and politicized) in the context of environmental conservation—where ideas about the ancient and the "primitive" are also salient—can provide clues for rethinking medical subjectivity in the era of the microbiome.