VOA慢速英語(yǔ):亞馬遜部落居民可抵制抗生素

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There are some people who have never come into contact with Western civilization. These people have microbes, tiny organisms, on and in their bodies that can do something amazing. They can make the most modern antibiotics useless.

That is one finding from new research in the journal "Science Advances." The researchers studied the bacteria and other microbes living in and on the Yanomami tribe. These people live in a village in the Amazon jungle far from other human settlements.

The Yanomami are some of the last people on the planet to have had contact with Western civilization. To scientists, this tribe provides an opportunity to observe the life of human microbes before humans settled down and developed civilizations.

Western diets and lifestyles have spread across the globe. With those diets and lifestyles also come conditions like obesity, diseases like diabetes and immune disorders. Some researchers wonder whether the microbes humans lost over time are partly the reason why we have some of these conditions.

This question is tied to an important discussion in scientific and medical communities. Some medical experts worry that antibiotics -- often life-saving medications -- are losing their power to fight disease. However, this new research suggests that the genes that let bacteria resist modern antibiotics may have always been there.

A remote and uncontacted village

The Yanomami people are hunter-gatherers. They live in small, remote villages deep in the Amazonian rainforest. Westerners first encountered Yanomami people in the 1960s.

In 2008 researchers arrived in one of their villages. People living there -- all 54 of them -- said they had never seen Westerners before. The Yanomami people and their chief permitted researchers to collect samples from their body.

A different kind of germ warfare

Scientists expected to find that the Yanomami microbes carried some antibiotic-resistant genes. That would not be surprising to them. In fact, many bacteria found in soil produce natural antibiotics, which help the bacteria survive in competitive environments. Some say it is all part of an ongoing bacterial battle.

But the researchers also found many genes in microbes that disarm man-made antibiotics that no known microbes produce.

This came as a big surprise to the researchers.

One of the researchers is a man named Gautam Dantas. Mr. Dantas is from the Washington University School of Medicine. This was a surprise, he said, because it shows the bacteria have the ability to adapt to many things, possibly even things researchers did not think they have been exposed to.

Silent resistance

This discovery is important. It might mean that antibiotics are losing their ability to fight disease. Antibiotics are currently our "wonder drugs." This research suggests that even those who have not been treated with antibiotics have bacteria with genes that may defeat them.

Mr. Dantas said these findings demonstrate the need to increase research for new antibiotics. If this does not happen, he warned, we are going to lose the battle against infectious diseases.

And, he said, the findings also show the need to use current antibiotics more carefully. Some doctors are campaigning to reduce the use of the drugs in patients who would recover without them. Some doctors oppose the widespread practice of treating healthy livestock, the animals we raise for food, with antibiotics to prevent illness.

There is an existing amount of antibiotic-resistant genes that are waiting to be switched on, Mr. Dantas said. When you use antibiotics -- whether in agriculture with livestock or in a clinic with patients -- you increase the amount of antibiotic-resistant genes.

Scientists are not the only ones concerned about resistance to antibiotics. Government leaders are also worried. In March, U.S. President Barack Obama announced a new five-year plan to fight antibiotic-resistant bacteria. He called the issue one of the most serious modern-day public health threats.

Before meeting with science advisors, President Obama told reporters at the White House that many people take antibiotics for granted. To take something for granted means to not fully see the value of something because it has been around for so long and is so common.

Here is Mr. Obama:

"We take antibiotics for granted ... and we're extraordinarily fortunate to have been living in a period when our antibiotics work. If we start seeing those medicines diminish in effectiveness, we're going to have big problems. And part of the solution here is not just finding replacements for traditional antibiotics -- it's also making sure that we're using antibiotics properly."

Diverse germs may help you fight disease

Researchers studying the Yanomami people found something else. After studying the population of microbes living in and on the Yanomami's bodies, the researchers said they found more diversity than in any other people they have ever studied. This diversity is more than other Amazonian farmers and much more than Americans.

The lead author of the study is Jose Clemente at the Icahn School of Medicine at Mount Sinai in New York. Mr. Clemente said that when traditional societies change to a Western lifestyle they lose this rich bacterial diversity. They also lose the benefits that come from having so many different kinds of germs living in and on the body.

For example, he said, the Yanomami carry bacteria that can prevent kidney stones. These bacteria were nearly absent in the other groups studied. He added that this study demonstrates the need to learn about the microbes in non-Western people before their microbial diversity is lost.

But how healthy are the Yanomami?

Another study by some of the same authors said Amazonian tribes that had more westernized lifestyles had higher rates of obesity than the Yanomami. On the other hand, the Yanomami had higher rates of undersized growth. The World Health Organization considers undersized growth a sign of poor nutrition.

New science

Microbiome science is a new field. Not much is known about this area of science. Even the idea that more microbial diversity is healthier is open to debate. Some scientists say that having less microbial diversity makes sense for people living westernized lifestyles. People who live this way spend less time outdoors and eat cooked, cleaned.

But most scientists agree more research into microbes is needed.

I'm Mario Ritter.

And I'm Anna Matteo.

Steven Bargona reported on the Yanomami research from Washington, D.C. and Megan Duzor reported on President Obama's plan. Anna Matteo adapted both stories for Learning English. Ashley Thompson and Mario Ritter edited the adapted story.

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Words in This Story

remote - adj. far away from other people, houses, cities, etc.

bacteria – n. any one of a group of very small living things that often cause disease

microbe – n. an extremely small living thing that can only be seen with a microscope

antibiotic – n. a drug that is used to kill harmful bacteria and to cure infections

resistant – adj. not affected or harmed by something

expose –v. to cause (someone) to experience something or to be influenced or affected by something

diversity – n. the quality or state of having many different forms, types, ideas, etc.