Gut microbes help packrats eat poison

Packrats can repeatedly eat poison if they have the right gut microbes.

Scientists had suspected this, but there wasn’t much evidence to support the idea, so a team decided to test it in desert woodrats (Neotoma lepida). Some populations of this species snack on a bush called creosote, which is toxic, while other groups leave it alone. When the creosote-eaters were given antibiotics, their gut microbes changed so that they couldn’t metabolize the toxins from bush. And when non-creosote-eaters were given fecal transplants from those that could eat the bush, the non-eaters could ingest more of the toxin.

The results, published July 20 in Ecology Letters, suggest that gut microbes expand the range of what planting-eating mammals can munch on and that  microbes may one day help livestock broaden their menu too.