Gut microbiota as key mediators of animal acclimation to temperature changes: mechanisms and interventions.

With the intensification of global climate change, temperature fluctuations profoundly affect animal physiology and health. Research has shown that the gut microbiota, as a critical bridge between the host and its environment, helps animals adapt to temperature changes by regulating intestinal barrier stability, immune function, and energy metabolism. This adaptive capacity underscores the indispensable role of gut microbiota in temperature change responses. In cold environments, animals increase food intake and activate brown adipose tissue to maintain body temperature, but prolonged exposure causes metabolic overload and gut microbiota imbalance. Chronic cold reduces beneficial bacteria and increases pro-inflammatory species, impairing intestinal barrier integrity and inducing systemic inflammation, ultimately leading to metabolic disorders and immunosuppression. Similarly, heat exposure leads to pathogenic overgrowth and immune dysfunction, reducing microbial diversity and increasing the abundance of harmful bacteria, ultimately impairing animal health. Furthermore, the gut-brain axis plays a central role in coping with environmental stress, as temperature change alters microbial composition and metabolites, impacting neurotransmitter synthesis and release, thereby regulating physiological states and emotional responses. Finally, targeted microbial interventions-such as fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, and postbiotics-are discussed as effective strategies to restore gut microbiota homeostasis, enhance host resilience to temperature change, and improve animal health under temperature fluctuations.