Intestinal bacteria trigger a hibernation-like state in homotherms via the gut-brain axis

The adaptation to low temperature has research value in the fields of spaceflight, disease treatment, and ecological evolution. However, continuous exposure to cold leads to hypothermia and death in homothermic animals. Interestingly, heterothermic animals can easily overcome this challenge. We transferred intestinal bacteria from hibernating Marmota himalayana into mice (homothermic animals) and successfully induced a torpor-like state. The mice exhibited typical characteristics of hibernation (torpor-like), such as the rectal temperature decreased by 3.72-4.58 °C, respiration rate and physical activity were down-regulated, and heat was concentrated in the brown adipose tissue. Those was associated with the Sphingolipid metabolism, regulated by Bacteroides, opened the temperature switch in the medial preoptic area and ventromedial hypothalamus through the "gut-brain axis". Our findings suggested that gut bacteria can regulate thermoregulation via the gut-brain axis and induce animals to adapt to low temperatures in a torpor-like state.