A captive desert woodrat, also known as a packrat, stands on a rock near branches from a toxic creosote bush.
A new University of Utah study shows how microbes in the gut play a key role in letting mammals such as woodrats digest and survive on creosote, juniper and other toxic plants. The researchers used antibiotics to kill gut microbes, rendering creosote-eating woodrats unable to digest the plant. They also transplanted feces from woodrats that ate creosote into woodrats that ate juniper. That transplanted fecal gut microbes gave the latter woodrats the ability to digest creosote.