Gut microbiota helps to maintain core body temperature under cold exposure.
It is known that microbiota, microorganisms which live in and on the host, are crucial to the regulation and balance of human and animal health. A relationship between gut microbiota and the host metabolic homeostasis has long been explored, with brown adipose tissue (BAT) shown to maintain host core body temperature during cold exposure. However, the potential impact of gut microbiota on this thermogenic process is unclear. Now, a study from researchers at the Chinese Academy of Sciences shows that gut microbiota plays an important role the way animals respond to cold exposure. The team state their data adds to the ever-growing catalogue of physiology and health conditions which are impacted by the gut microbiome. The opensource study is published in the journal Cell Reports.
Previous studies show during cold exposure animals sustain their body temperature by activating heat production from BAT and the browning of white adipose tissue. Evidence from animal studies records the effectiveness of BAT based thermogenesis in stimulating energy expenditure to reduce obesity, known as metabolic homeostasis. The capacity for brown fat thermoregulation is thought to come from genetic variability in response to environmental signals, suggesting a role for the gut microbiome. The current study investigates how BAT and white adipose tissue respond to temperature challenges in mice lacking gut microbiota.
The current study utilises an antibiotic cocktail to eradicate gut microbiota in mice to evaluate the function of gut microbiota on the activation of BAT. Results show that animals lacking gut microbiota had impaired thermoregulation. Data findings show that removal of the gut microbiota blunted the increase in the expression of uncoupling protein in BAT and reduced white adipose tissue browning.
Results show the imbibing of the microbiotic metabolite butyrate, a metabolite thought to activate BAT via a direct gut-brain neural circuit, increased the thermogenic capacity of the animals, reversing the lack of microbiota. Data findings show that gut microbiota contributes to upregulated thermogenesis in the cold environment and that this may be partially mediated via butyrate.
The team surmise their study shows an intact microbiota is essential for regulating body heat in response to cold exposure, and microbial-derived butyrate may be a mediating factor in this role. For the future, the researchers state it will be interesting to discover if known changes in the human microbiome with age contribute to susceptibility to hyperthermia, and if modulating these age-related changes will afford elderly people more protection.
Source: Chinese Academy of Sciences