A study published last week in Cell explores the microbiome of the gut in both mice and humans, and it’s responses to changes in its biological rhythm. Researchers performed many experiments that were comprised of altering the dark-light conditions in which mice were kept, as well as the feeding times of mice.

Many important results were found from the multiple variations in experimental conditions to which the researchers subjected the mice. First, researchers uncovered that the microbiome has time-of-day- specific differences in function and composition. Evidence suggests that feeding patterns dictate this fluctuation. After mimicking jet-lag in mice, compared to a control group, these mice exhibited imbalances in their gut microbiome. It was later found that this imbalance could be transferable from jet-lagged mice to mice raised germ-free, through the fecal transfer of the gut microbiome. An experiment was also done in which jet-lagged and control group mice were fed high fat diets. The jet-lagged mice exhibited enhanced weight gain and glucose intolerance. Antibiotic treatment showed a decrease in these symptoms. Lastly, a study was done in humans who were subjected to jet-lag, which suggested that the microbiome of humans also undergoes daily oscillations, and that disruption of this rhythm can lead to imbalances in the microbiome and in human metabolism. The human study was only done with two individuals and fortunately, their microbiomes returned to normal after just two weeks though still raising questions about the impact that too much travel and jet-lag could have on health.

The experiments done in this study opens the door for further research on the microbiome’s sensitivity to changes in a human’s biological clock, as well as the impacted microbiome’s influence on the metabolism of its host.