Gut Bacterial Communities Vary across Habitats and Their Diversity Increases with Increasing Glucocorticoids in Toad Tadpoles

The gut microbiome is important for host health and can be influenced by environmental hormonal changes. We studied the interactions between anthropogenic land use, glucocorticoid hormones, bacterial communities in common toads (Bufo bufo). sampled tadpoles from ponds of three habitat types (natural, agricultural, urban ponds), examined composition using amplicon sequencing 16S rRNA gene, measured associated stress physiology water-borne hormones. Tadpoles different significantly differed composition. However, richness, Shannon diversity, Firmicutes to Bacteroidota ratio did not vary with type. In contrast other studies, we found a positive correlation baseline corticosterone release rate diversity. Stress response negative feedback were correlated These results suggest that, despite alterations intestinal due land-use change, toad habitats may maintain their physiological terms “gut-brain axis”.