When scientists first made contact with an isolated village of Yanomami hunter-gatherers in the remote mountains of the Amazon jungle of Venezuela in 2009, they marveled at the chance to study the health of people who had never been exposed to Western medicine or diets. But much to their surprise, these Yanomami’s gut bacteria have already evolved a diverse array of antibiotic-resistance genes, according to a new study, even though these mountain people had never ingested antibiotics or animals raised with drugs. The find suggests that microbes have long evolved the capability to fight toxins, including antibiotics, and that preventing drug resistance may be harder than scientists thought.
The human gut harbors trillions of bacteria, collectively known as the microbiome. Several recent studies have found that people in industrialized nations host far fewer types of microbes than hunter-gatherers in Africa, Peru, and Papua New Guinea, for example. This is intriguing as the absence of diverse bacteria has been linked to obesity, diabetes, and many autoimmune disorders, such as allergies, Crohn’s disease, celiac disease, and colitis.
The discovery is troubling because it suggests that “antibiotic resistance is ancient, diverse, and astonishingly widespread in nature—including within our own bodies,” says anthropologist Christina Warinner of the University of Oklahoma in Norman, who is not a co-author. “Such findings and their implications explain why antibiotic resistance was so quick to develop after the introduction of therapeutic antibiotics, and why we today should be very concerned about the proper use and management of antibiotics in both clinical and agricultural contexts.”