The divergent effects of moderate climate warming on the gut microbiota and energetic state of cold-climate lizards from open and semi-closed microhabitats

Understanding the physiological responses to warming temperatures is critical for evaluating the vulnerabilities of animals toclimate warming. The physiological responses are increasingly affected by gut microbiota. However, the interactions betweenphysiological responses and the gut microbiota of sympatric animals from various microhabitats in the face of climate changeremain largely unknown.To evaluate the effects of warming temperatures on animals from different microhabitats, we compared locomotor performance,metabolic rate, growth, survival, and gut microbiota of two sympatric ectothermic species (Eremias argus and Takydromusamurensis) from open and semi-closed microhabitats under present and moderate warming climate conditions, respectively. Wefound that locomotor performance and growth rates of snout-vent length (SVL) were enhanced in both lizard species by warmingclimate. Interestingly, warming temperatures enhanced resting metabolic rates (RMR) in the open-habitat lizard, E. argus, butdepressed them in the semi-closed habitat lizard, T. amurensis. Reversely, the metabolism-related gut microbiota was not affectedby warming in E. argus, whereas it was significantly enhanced by warming in T. amurensis, indicating a plausible compensatoryeffect of the gut microbiota on the metabolic regulation of T. amurensis. Furthermore, warming likely improved immunity in bothlizard species by significantly reducing pathogenic bacteria while increasing probiotics.This study found that high-latitude sympatric lizards from both open and semi-closed habitats were beneficial to warmingtemperatures by physiological modification and regulation of the gut microbiota and highlighted the importance of integrating thephysiology and gut microbiota in evaluating the vulnerability of animals to climate warming.