Dominant Effect Of Host Genetics On Skin Microbiota Composition In Homeostasis And Wound Healing

Animal microbiota are shaped and maintained not only through microbiota-environmental interactions but also through host-microbiota interactions. The effects of the microbiota on the host has been the source of intense research in recent years, indicating a role for resident microbes in a range of conditions from obesity and mood disorders to atopic dermatitis and chronic wounds. Yet the ability of hosts to determine their microbiota composition is less well studied. In this study, we investigated the role host genetics plays in determining skin microbiota. We used 30 different mouse strains from the advanced recombinant inbred mouse panel, the Collaborative Cross, with PERMANOVA, GWAS and PCA-based GWAS analyses to demonstrate that murine skin microbiota composition is strongly dependent on murine strain. In particular, a quantitative trait locus on chromosome 4 associates both with Staphylococcus abundance and principal-component multi-trait analyses. Additionally, we used a full thickness excisional wound healing model to investigate the relative contributions from the skin microbiota and/or host genetics on wound healing speed. Wound associated changes in skin microbiota composition were observed and were in many instances host-specific. Despite reaching statistical significance, the wound-associated changes in skin microbiota accounted for only a small amount of the variance in wound healing speeds, with the majority attributable to mouse genotype (strain) and age. Host genetics has a significant impact on the skin microbiota composition during both homeostasis and wound healing. These findings have long reaching implications in our understanding of associations between microbiota dysbiosis and disease. ### Competing Interest Statement The authors have declared no competing interest.