Indians from an isolated tribe in the Amazon show great resistance to antibiotics, even the most recent drugs. A discovery that worries researchers.
The Yanomami Indians are one of the most numerous peoples in South America. They live in the tropical forest of the mountains located in northern Brazil and southern Venezuela. Accustomed to violent contact with the artisanal miners, some of them nevertheless live in isolation. And it is among them that American researchers have made a disturbing discovery.
A more varied microbiome than in rural areas
A Yanomami tribe in the Amazon rainforest does indeed appear to be highly resistant to antibiotics, even though its members have hardly ever been in contact with the outside world, researchers said in a study published in the journal. Science Advances.
The tribe was first spotted by aerial observation in 2008 and was visited by a medical team a year later. The latter took saliva, skin and stool samples from 34 members of the tribe.
Scientists have found that the “microbiome” of members of this tribe – the bacteria, fungi and viruses that live in our bodies – is much more diverse than that of rural communities in Venezuela and Malawi. It is even twice as diverse as that observed in a benchmark group of Americans.
Healthy villagers
These villagers are generally healthy, no doubt thanks to this microbiome which “contains perhaps the highest levels of bacterial diversity ever seen in a human group,” the scientists note. As a comment, the Washington University School of Medicine team confides that although “the Yanomami wear T-shirts, have machetes and tin cans, suggesting contact with the outside world, they do not ‘have not been exposed to many elements of contemporary life, contact likely to reduce this microbial variety. ”
No sample of their food
Scientists also point out that the variety of the microbiome decreases, in particular when we eat industrial food, when we take antibiotics, when we wash our hands with anti-bacterial gel and when we give birth by cesarean section. Some microbes also seem to have a protective effect on health, for example preventing the formation of kidney stones.
The researchers also saw no cases of obesity or malnutrition among members of this tribe, “who live on fish, frogs, insects, plantains and a fermented melon drink.” said to the Swiss Telegraph Agency (ats) Maria Gloria Dominguez-Bello, the main author of the study. However, “no sample of their food or drink was taken, which could give indications on the diversity of their intestinal flora,” she continued.
Genes resistant to the latest antibiotics
She adds that her researchers “expected to find some resistance to antibiotics in this tribe, given the presence of bacteria-resistant genes in the soil, which have been around for millions of years. And it would have made sense for these genes to migrate to men too, without even the use of antibiotics.
But what surprised these researchers a lot is that members of this tribe have genes 30 times more resistant to antibiotics than others. And these genes have been shown to be resistant to the latest antibiotics. “What worried us was that these genes could inactivate modern synthetic drugs,” said another study author, Guatam Dantas, of the University of Washington School of Medicine.
The need to find new antibiotics
Modern antibiotics began to be developed in the 1940s, notably penicillin, until the 1970s. Most of them were taken from the soil. But the very wide use which is made of it among men and animals has generated resistance which worries more and more. Some even predict a new era when these antibiotics will no longer work. “This study highlights the need to develop research towards new antibiotics because otherwise we will lose this battle against infectious diseases,” concluded Guatam Dantas.
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