Potential role of the gut microbiota in synthetic torpor and therapeutic hypothermia

Figure 1 Role of the gut microbiota in the hibernation physiology. In natural hibernators, the gut microbial ecosystem is capable of an adaptive response along the hibernating cycle. Variations in the gut microbiome structure during torpor are functional for several physiological aspects involved in hibernation, such as the maintenance of the good functionality of the intestinal epithelium and the regulation of the metabolic and immunological homeostasis. During interbout arousals, metabolites from a cold and fasting-adapted gut microbial ecosystem reach the enterocytes, the underlying immune cells, as well as the circulation. In each district, the microbial metabolites exert essential functions for the maintenance of the host homeostasis along the hibernating period. In particular, the microbiome derived short chain fatty acids are of strategic importance, being at the same time, a valuable energy source for enterocyte metabolism, a regulator of gluconeogenesis, fat storage, and insulin sensitivity, and, finally, a potent immunomodulator, favoring an anti-inflammatory immune system layout.