Gut and skin microbiota of Bufo gargarizans tadpoles respond differently to temperature

Gut and skin microbiota impact host physiology and can be influenced by environmental changes, however, their reactions to rising environmental temperatures remain unclear. In this study, Bufo gargarizans tadpoles were exposed to 22 °C (control) and 27 °C (high-temperature) and the gut and skin microbiota were sampled at 24, 72, and 144 h to assess the effects of short-term elevated temperatures. Results revealed that the richness index (ACE, Chao, Sobs) and Pd index of gut microbiota were significantly affected by stress time, while the diversity index (Shannon, Simpson) was significantly affected by the interaction of temperature and time. The response of alpha diversity of skin microbiota to temperature and time was not significant, and only Pd index was affected by the interaction between temperature and time. No significant changes in microbial composition (beta diversity) were observed in either skin or gut microbiota across three sampling time points under both treatments. After 144 h of high-temperature stress, KEGG functional prediction indicated that basic metabolic pathways involving DNA replication and amino acid biosynthesis were significantly downregulated in the gut microbiota, while sulfur metabolism was upregulated. For the skin microbiota, pathways related to drug resistance, cancer, and metabolism showed significantly decreased abundance, whereas homologous recombination and metabolic pathways were significantly elevated. High temperature accelerated the developmental rate of tadpoles, however, their growth metrics including weight, total length, snout-vent length, and body width were significantly inhibited at equivalent developmental stages. This study elucidates the response patterns of amphibian hosts and their commensal microbiota to short-term high-temperature stress, providing insights into the implications of global climate change for amphibian survival.