We conducted a controlled biodiversity intervention using a wild-derived rodent model (bank vole). Animals were exposed for 4–5 weeks post-weaning to either sterile bedding (Control), soil from national parks (Park), or soil from urban greenspaces (Urban). Gut microbiota was analyzed using high-throughput sequencing of bacterial and fungal markers, and host immune responses were assessed through RNA sequencing of colon tissue.
Key achievements include:
-Soil exposure significantly altered gut microbiota composition and organization.
-Gut fungi showed a stronger response than bacteria, with many species acquired directly from soil.
-Urban soil exposure increased the abundance of potentially pathogenic bacterial genera (Allobaculum, Brachybacterium).
-Host gene expression revealed activation of innate immunity in animals exposed to urban soil, marked by upregulation of epithelial defense genes.
-Natural forest soils promoted immune tolerance, while urban soils triggered stronger immune activation.
All scientific objectives were met. All data and workflows have been archived in open repositories (ENA and Zenodo) to ensure transparency and reproducibility.