Study discovered that carnivore gut bacteria provide insight into condition of natural environments

According to a new study, the microbial community in the intestines of wild martens (Martes americana) living in relatively pure natural settings differs from the gut microbiome of wild martens living in places more strongly touched by human activities. The discovery reveals a new tool that will enable academics and wildlife managers to measure the health of natural habitats.
“Specifically, we discovered that wild martens in more undisturbed regions have more carnivorous diets than martens in human-affected areas,” explains Erin McKenney, co-lead author of the study and associate professor of applied ecology at North Carolina State University.

Marten are tiny animals that are closely related to weasels, ferrets, and mink. “This result, together with our earlier study on carnivore microbiomes, shows us that the microbial ecosystems in carnivore stomachs can vary greatly, reflecting a carnivore’s environment,” McKenney adds. “This means that we can identify how much people are harming a region by examining the gut microbiomes of carnivores who reside there, which can be done by testing wild animal excrement. In practise, this research reveals a useful tool for monitoring the health of natural ecosystems.”

“Our objective here was to investigate how, if at all, human disturbance of a landscape impacts the gut microbiota of American martens who reside in that area,” explains Diana Lafferty, co-lead author and assistant professor of biology at Northern Michigan University. “And the answers were quite plain here.”
The researchers obtained gut microbiota data from 21 martens for the study. During a lawful trapping season, sixteen martens were caught. The remaining five were successfully captured and released at the Huron Mountain Club in Michigan’s Upper Peninsula.
“The Huron Mountain Club is very relevant for our study because it’s relatively virgin – one of the biggest, primaeval forests in the eastern United States,” adds Lafferty.

“This makes it a wonderful contrast to the 16 martens gathered, which were obtained in areas more damaged by human activity.”
The researchers discovered that the gut microbiomes of marten captured in the Huron Mountain Club’s pristine forest were clearly unique from marten collected elsewhere.
“This reflects the fact that marten in relatively pure forest may graze at a higher trophic level, which means they hold a higher position in the food web,” Lafferty explains. “In other words, marten in relatively pristine forests have a more carnivorous diet, whereas marten in more populated regions are more omnivorous.”

Essentially, the data show that a disrupted environment causes a considerably altered diet, which is reflected in their gut microbiomes.”
“It’s also worth noting that we were able to trap and release the marten in Huron Mountain Club during the dead of winter because we designed and built custom box traps to protect them from the elements,” says Chris Kailing, a co-author of the paper and former Northern Michigan University student who worked on the project. “This is interesting since it allows for winter sampling for future animal studies even in difficult winter circumstances.”
“This is the most recent chapter in a collection of research that is assisting us in understanding carnivore gut microbiomes,” McKenney adds.

“Carnivore gut microbiomes are naturally more varied than other species’ gut microbiomes. This work adds to the developing understanding that all of this variation is not just noise. This variety is caused by the nutritional landscape that carnivores have access to, which in turn reflects the health of the ecosystem that carnivores occupy. This means that studying the gut microbiota of wild predators can provide us with valuable information about the environments in which they dwell.”