Paper short abstract:

The human microbiome is a pathway by which culture becomes biologically embodied. Drawing from a biocultural study of infant development in El Salvador, the author illustrates the field’s potential to imagine a more complete picture of humanity's cultural and biological variation, origins, and futures.

Paper long abstract:

Emerging research on the human microbiome indicates that the gut should be seen as a unique anatomical niche where biological and social phenomena interact to become mutually constitutive. The microbiome initiates development at birth and stabilizes in the first year, performing key functions for its host. In contrast to other important biological systems, however, the microbiome is entirely sourced from the external world during development and throughout the life-cycle. In return the microbiome impacts the daily-lived experience and outer world of its human host. Thus a sophisticated understanding of the human gut demands an integrated biocultural framework that explores the social lives of both humans and their microbial partners.

This paper draws from a longitudinal, biocultural study of infants from a semi-rural village in El Salvador. Beyond the commonly studied factors of birth mode and early feeding, I explore how distal political economic processes impact more proximal household ecologies and ultimately the infant microbiome. In this way I elucidate a pathway of embodiment through which culture becomes biology. Next I critically examine the promises and pitfalls of this nascent field, and its potential to draw a more complete picture of humanity's cultural and biological variation, origins, and futures.