Hybrid Zones, Bio-objectification and Microbiota in Human Breast Milk Banking

This paper critically examines hybridity and complexity in human biobanking, focusing on current forms of human milk banking in Madrid (Spain). We present and analyze three practices where human breast milk is stored and circulated: the “12 de Octubre” human milk bank, set in a neonatology unit and based on altruistic donations; informal human milk sharing among mothers; and drug-development practices that use donated human milk as a source of probiotics. Our analysis show that these practices rely on complex socio-technical assemblages, which are also characterised by hybrid zones and points of intersection between them. By understanding bacteria as a boundary object, we analyze the entanglements, disentanglements and re-entanglements of microbiota in the mechanisms of human milk bio-objectification that each of these biobanking practices entails. The distinctions or confusions between “virtuous” and “wicked” bacteria are part of a complex choreography where political, technical and sociocultural aspects get entangled.