July 22, 2014
Herbivores Able To Dine On Toxic Plants Thanks To Gut Microbes
Woodrats lost their ability to eat toxic creosote bushes after antibiotics killed their gut microbes. Woodrats that never ate the plants were able to do so after receiving fecal transplants with microbes from creosote-eaters, University of Utah biologists found.The new study confirms what biologists long have suspected: bacteria in the gut – and not just liver enzymes – are “crucial in allowing herbivores to feed on toxic plants,” says biologist Kevin Kohl, a postdoctoral researcher and first author of the paper published online July 21 in the journal Ecology Letters.
The study of woodrats, also known as packrats, raises two concerns, according to Kohl and the study’s senior author, Denise Dearing, a professor and chair of biology:
– Endangered species may lose diversity of their gut microbes when they are bred in captivity. When they are released to the wild, does that leave them unable to consume toxic plants that once were on their menu?
– Livestock like cows often are fed antibiotics to promote growth. Does that impair their ability to eat toxic plants like locoweed when drought reduces pasture grass?
The study of woodrats someday might impact farming practices in arid regions, where toxic plants like creosote and juniper are abundant. Livestock now can’t graze on these cheap food sources. Could interspecies transplants of gut microbes help livestock expand their dining menu? Kohl says he’d like to transplant woodrat gut microbes into sheep or goats to find out if that increases their tolerance to toxic foods.
“Juniper is expanding its range, and ecologists and land managers are concerned,” he says. “Farmers are interested in getting their sheep and goats to eat juniper.”
The study was funded by the National Science Foundation. Dearing and Kohl conducted the research with three other University of Utah faculty members: human geneticist Robert Weiss, biochemist James Cox and biologist Colin Dale.