Bacteria in the Guts of Isolated Tribespeople Have Antibiotic Resistance

Antibiotic resistance is a huge issue in hospitals across the globe. Now, scientists have found antibiotic resistance genes in the bacterial flora of a South American tribe that has never been exposed to antibiotic drugs.

In 2009, researchers stumbled on the remote tribe of Yanomami Ameridians in mountainous southern Venezuela. This tribe had been isolated from other societies for more than 11,000 years, which meant that individuals had some of the most diverse collections of bacteria recorded in humans. Within this bacteria were genes that were wired to resist antibiotics.

"This was an ideal opportunity to study how the connections between microbes and humans evolve when free of modern society's influences," said Gautam Dantas, one of the researchers, in a news release. "Such influences include international travel and exposure to antibiotics."

Thousands of years before people began using antibiotics to fight infections, soil bacteria began producing natural antibiotics to kill competitors. Similarly, microbes evolved defenses to protect themselves from the antibiotics that their bacterial competitors would make, likely by acquiring resistance genes from the producers themselves through a process known as horizontal gene transfer.

Scientists have long wondered whether the diversity of specific bacteria improved or harmed our health. The microbiomes of people in industrialized countries are actually about 40 percent less diverse than in tribespeople that have never been exposed to antibiotics.

"Our results bolster a growing body of data suggesting a link between, on one hand, decreased bacterial diversity, industrialized diets and modern antibiotics, and on the other, immunological and metabolic diseases-such as obesity, asthma, allergies and diabetes, which have dramatically increased since the 1970s," said Maria Dominguez-Bello, one of the researchers. "We believe there is something occurring in the environment during the past 30 years that has been driving these diseases, and we think the microbiome could be involved."

The findings reveal a bit more about the connection between modernity and the microbiome. They also show that antibiotic resistance can develop even in isolated populations.

"We've seen resistance emerge in the clinic to every new class of antibiotics, and this appears to be because resistance mechanisms are a natural feature of most bacteria and are just waiting to be activated or acquired with exposure to antibiotics," said Dantas.

The findings are published in the journal Science Advances.

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).