科学美国人60秒:Bear Gut Microbes Help Prep Hibernation

Does a bear produce feces in the woods? And do enterprising researchers then scoop that poop to analyze its microbial composition? You bet they do! And what they find is that the ursine intestinal microbiome changes dramatically during hibernation, an internal microbial shakeup that could help bears do their big metabolic chill.

Brown bears spend the summer beefing up in preparation for their winter snooze. They eat and eat and they pack on the pounds. Yet despite this seasonal gluttony and weight gain, the bears appear to be immune to developing diabetes or the other metabolic disorders that befall yo-yo dieters of the human variety.

So researchers theorized that gut bacteria might play a role. To check out that idea, the scientists collected scat from captured wild brown bears both during their season of feasting and during hibernation. And in case you’re wondering, they went in and got the stuff before it even hit the ground. If you get my drift.  

An analysis of the excrement showed that bears’ summer bacteria are more diverse and include species that tend to promote energy storage. What’s more, when the researchers stripped mice of their own microbes and gave them the bacteria from bears, the rodents that received the summer sampler got fatter than those with the winter set—evidence that the microbiome is indeed affecting metabolism. The results appear in the journal Cell Reports. [Felix Sommer et al, The Gut Microbiota Modulates Energy Metabolism in the Hibernating Brown Bear Ursus arctos]

The researchers do not yet know whether fiddling with our own gut bacteria could help us shed excess weight. Or whether any such microbial diet plan would necessitate a very long winter’s nap.

—Karen Hopkin