According to a new study, the composition of gut microbes changes upon cold exposure and this promotes energy uptake and increases the amount of brown fat in the body.
Researchers have provided a mechanism of how the body develops tolerance to cold. The microbes found in the gut, called gut microbiota, not only help in digestion but also in energy metabolism. In a paper published in Cell, the study found that mice exposed to cold temperature for up to 10 days had increased food consumption, high caloric intake, and more brown fat. In comparison, mice treated with antibiotics to kill gut microbes had reduced tolerance to cold and decreased body temperature, which suggested that gut microbes play a role in energy metabolism at low temperatures.
Upon examination of the gut bacteria in mice, the study found that cold exposure caused a change in the gut microbial composition. This altered gut microbiota helped develop tolerance to cold by: 1) increasing insulin sensitivity, which stimulates glucose uptake as a response to high blood sugar level and increased food consumption; 2) increasing the brown fat in the body, which helps protect against obesity and promote higher energy usage; and 3) increasing the surface area of the intestines to promote nutrient absorption.
Based on the results, the changes in gut microbiota during cold exposure is an adaptation that helps the body become more efficient in extracting energy from food to generate body heat and tolerate cold temperatures.
Chevalier C, Stojanovic O, Colin DJ,…Zamboni N, Hapfelmeier S, Trajkovski M. Gut microbiota orchestrates energy homeostasis during cold. Cell. 2015 December; 163: 1360-1374. DOI: 10.1016/j.cell.2015.11.004
Written by Ana Victoria Pilar, PhD