It is known that during cold exposure animals sustain their body temperature by activating heat production from Brown Adipose Tissue (BAT), promoting “browning” of white adipose tissue. As shown in mice experiments by John R Speakman, CAS Institute of Genetics and Developmental Biology, groups of gut microbiota where eradicated using different antibiotics. The animals lacking gut microbiota showed impaired thermoregulation. The results where corroborated in germ-free mice. The effect could be because, in the absence of an intact microbiome, the animal is unable to digest sufficient quantities of food to meet elevated energy demands in the cold, and the impact on BAT is a secondary effect. However, the team also showed that addition of the bacterial metabolite butyrate increased the thermogenic capacity of antibiotic-treated mice. This suggests that microbiota plays an important signaling role in the process that stimulates cold-induced thermogenesis. 

CAS news release, March 6, 2019