Social Microbiome Assembly, Function, and Impacts on Host Health

PROJECT SUMMARY Human health is profoundly impacted by our social interactions and our associated microbes. Social isolation and microbiome perturbations are both linked to a myriad of pathologies including neurological and immunological disorders. Emerging evidence reveals that our microbiomes are shaped by our social interactions. For any social animal, we can define its associated microbial community that assembles through social interactions as its social microbiome. We propose to establish a Social Microbiome Program at the University of Oregon to investigate the hypothesis that social microbiomes are major drivers of host health and sociality. Our team’s pioneering research, using a new zebrafish model for the precise manipulation of host social and microbial interactions, reveals that social microbiomes promote normal host development and mitigate the virulence of microbiome members. Our recent work has revealed that social microbiomes are enriched for shared, co- occurring networks of bacteria. We hypothesize that these bacterial consortia are co-adapted to the host environment, with expanded collective capacities to utilize abundant resources, such as extracellular glycans, and to overcome nutritional scarcities, such as limiting iron. We show that bacterial processing of host glycans contributes to features of host neurodevelopment important for social behaviors. Furthermore, we show that microbiome provisioning of scavenged iron mitigates bacterial virulent tendencies toward host tissue destruction. We hypothesize that in the absence of these bacterial activities in social microbiomes, neurodevelopmental social deficits and sickness behavior impair social microbiome assembly and select against bacterial traits important for host co-adaptation and co-evolution. We will test these ideas about the assembly, functions, and health impacts of social microbiomes through a coordinated, multidisciplinary research program. Our team brings together leaders in the areas of microbial ecology, neurodevelopmental biology, animal and bacterial behaviors, and bacterial pathogenesis. Together we will innovate new approaches to studying microbiomes in animal social groups.