Woodrats can 'Stomach' Anything: Rodent Feasts on Poisonous Plants, Thanks to Gut Microbes

Meet the desert woodrat; a rodent species native to the western North American deserts.Though quite tiny in size, make no mistake; these creatures can "stomach" just about anything.

A recent study conducted by researchers at the University of Utah found that as many enjoy feasting on creosote bush that's covered in toxic resin, the rodent's gut bacteria allows them to consume a poisonous compilation of plants. 

Many toxic chemicals can be found in this regimen of foilage, including nordihydroguaiarectic acid (NDGA)--a chemical that wreaks havoc on the liver and kidneys of other lab mice.  For any creatures that consume these foods, they require a mechanism that helps protect them from the toxic chemicals that the plants produce every day. 

Researchers predict that some 17,000 years ago, woodrats learned to acquire novel toxin-degrading gut microbes to adapt to climate and vegetation changes, which included the digestion of poisonous plants. 

"For decades, scientists have thought that gut microbes or gut bacteria might help mammals eat poisonous plants, but there really hasn't been a thorough test of that idea. We conducted a series of experiments to show this was the case", said lead study author Kevin Kohl, a postdoctoral researcher at the University of Utah, via Uncover California.

For the study, researchers performed three experiments using two kinds of woodrats--juniper eaters from the Great Basin desert and creosote eaters from the Mojave Desert. All were captured and kept on a diet of rabbit feed in a lab.

Researchers integrated the fecal matter into the rats' food, which is already a common part of a woodrat diet.

"We decided to feed the feces to our woodrats," Kohl said. "They do this by themselves. They eat their own feces, or poop, all the time. So what we did is we collected feces and ground it up and mixed it into their food so they would have to eat it."

Findings revealed that after ingesting feces--or gut microbes--from creosote eaters, juniper eaters were able to stay on the creosote diet for 11 days without losing much weight. However, 65 percent of the juniper eaters that ate feces or other juniper eaters didn't gain microbes that detoxify creosote, which caused them to lose 10 percent of their weight by day 11 on a creosote diet.

Researchers also found that when the rodents did not get transplants of creosote-detoxifying microbes, their urine was more acidic; this suggests that their livers had to expend more energy to degrade the creosote toxins.

In the future, researchers said these findings could potentially impact farming practices in arid regions where toxic plants are abundant. However, the concept of fecal transplants is nothing new. In the medical field, they have been used in enemas to transfer fecal matter from one person to another 

More information regarding the findings can be seen via the journal Ecology Letters.