UC Davis

This dissertation examines the legacy of germfree animal research in 21st-century human microbiome science. I show how the scope and diversity of human-associated microorganisms are being revealed through a deep cultural imagination of life in the absence of microbes. Across professional and popular scientific writing as well as fiction, I uncover a pervasive rhetorical maneuver I term speculative germfreeness: the imagination of aseptic catastrophe, at the nested scales of individual bodies, societies, and planets, deployed to prompt readers into revaluing the microbes that surround them. Speculative germfreeness is a cornerstone of contemporary microbiome discourse, essential to its claims for the importance of microbiome research in transcending the conventional paradigm of microbial eradication. Chapter 1 surveys the origins of germfree animal research in the late nineteenth century and its first adoption as a speculative device in the fiction of H. G. Wells. The chapter documents the historical imagination of germfree planets and societies in fiction and in popular science and concludes by showing how microbiome scientists and journalists draw on these precedents. Chapter 2 follows the thread of germfree disaster on a smaller scale in examining how fiction and popular science have told stories of bodies, both animal or human, confined to germfree bubbles. I detail how microbiome discourse reworks these narratives as parables for the folly of the antibiotic approach to microbial life. In Chapter 3, I argue that obstetric microbiomics is rewriting the stories of germfree disaster fiction in order to frame birth as a consequential passage between the germfree uterus and the germy planet. The chapter suggests that these rewritings cast mothers as singularly responsible for seeding their children’s nascent microbiomes and also burden them with the obligation to mother the microbial planet itself. Finally, Chapter 4 demonstrates how microbiome research, in its recent shift to translational metagenomics, has moved away from earlier themes of germfree disaster by developing novel metaphors of human-bacterial conversation. I argue that the ideal of speaking with one’s microbiome loosens the strictures of germfree obligation by establishing bacteria as agential participants in a conscientious human-microbial partnership.