Skin ulcers and microbiota in Rana dybowskii: Uncovering the role of the gut-skin axis in amphibian health

Amphibians' gut and skin microbiota are vital for host health. Ulcers may affect the skin microbiota, with unknown impacts on the gut microbiota. Skin diseases could influence both, but research on their interrelationships is limited. The cutaneous and gut microbiota of healthy and ulcerated Rana dybowskii were analyzed with Illumina sequencing. The result showed healthy frogs showed greater alpha diversity in skin microbiota than ulcerated ones, with no gut microbiota difference. Bray -Curtis and unweighted UniFrac distances revealed distinct skin microbiotas in healthy versus ulcerated groups and significant gut microbiota differences only in Bray -Curtis. Linear discriminant analysis of effect size (LEfSe) showed that ulcerated skin groups were enriched in Proteobacteria and healthy in Actinobacteria. A variety of analyses revealed that diseased frogs, unlike healthy ones, exhibit similar skin and gut microbiota, suggesting disease impacts microbiota relationships and composition. Using the indicator method, identify key bacterial species indicating healthy or diseased status in the frog's skin and gut microbiota. There were significant differences in skin and gut microbiota functions between diseased and healthy frogs, with disease impacting bacterial community structure and physiological functions. Research on R. dybowskii indicated disease aligns the skin and gut microbiota, affecting composition and function, with distinct bacterial indicators for health and disease status. This research underscores the complex interplay between skin and gut microbiota in amphibian health, highlighting implications for disease understanding and conservation strategies.