"The Littlest Creatures that Live Inside Us": Public understandings influencing microbiome-related behaviors

The impact of behaviors on the microbiome, and in turn its effects on health, are increasingly recognized by the scientific and medical communities. Yet little is known about public understandings of the microbiome and the relationships with health. We developed a semi-structured interview tool covering topics from microbiome composition to behavioral factors affecting microbiomes and related health throughout the life course. Drawing on semi-structured interviews conducted in 2021-22 with 32 US women purposefully recruited from 5 demographic categories (with pets, chronic illness, young children, complementary and alternative medicine use, and elders), we explore perspectives on topics including microbiome and diet, medicine use, cleaning practices, and travel. We conducted a thematic analysis, tallied response frequencies of elicited themes, and plotted emerging themes on semantic maps to provide visual representations of connections between concepts, and commonly mentioned metaphors to identify promising new lines of inquiry on public understandings of the microbiome. We observed interconnections between domains, as shown in semantic maps, and examples of ecological and militaristic analogies. Participants used analogies to estimate duration of microbiome disruption and recovery. Metaphors provide scaffolding for organizing new information about the microbiome and influence how people make choices about when and how to kill or promote microbes in their bodies and their environment. Characterizing these public understandings of microbiomes and linkages to health behaviors among different demographic groups is critical to designing and implementing health education and policy and informing future research inquiries in a participatory way through public-research collaborations.