Preserving the ground beneath the paws: does the biodiversity hypothesis matter for wildlife health?

Mounting evidence supports the biodiversity hypothesis stating that contact to immunoprotective factors in the environment is required for development of a balanced immune system, explaining the prevalence of allergies and other inflammatory disorders in humans inhabiting post-industrial societies. Yet, while urban areas are the most rapidly expanding ecosystems on Earth, little is known how the biodiversity hypothesis applies to wildlife. We performed a soil exposure experiment using the ecological model bank vole (Myodes glareolus), where laboratory-born vole pups were exposed to different forest soil mixtures and sterile bedding in individually ventilated cages for four weeks and monitored metataxonomic changes in gut microbiota. Treatment soil was collected from urban forests and national parks, considering that soil microbiota can greatly differ between levels of human development index. We found that soil treatment decreases species evenness and increases dispersal in beta diversity estimates in faecal samples compared to sterile control. This dataset will be further analyzed for inflammation markers such as Foxp3 and Il-17 using qPCR. These data can inform conservation of soil microbiomes and enhance rewilding interventions, and also inform planning of urban greenspaces and improve domestic and zoo animal wellbeing.