Microbe Hunters

Deep in the Amazon Rainforest, scientists search for the micro-organisms that lived inside ancient humans

In the Amazon
In the Amazon, María Gloria Domínguez-Bello and her team collected about 1,500 DNA samples to identify any microbe species that modern medicine may have wiped out. Photo courtesy of the Smithsonian Channel

Though modern medicine benefits people far and wide, pockets of the world remain untouched by it. In these isolated areas, people don’t know about amoxicillin, and they don’t live with air filters, daily showers or the power of Purell. Diets there favor starch and fiber, with very few preservatives.

María Gloria Domínguez-Bello, a microbiologist at the University of Puerto Rico, thinks that the mix of microbes living within and on people in these places—their microbiome—may be close to that of more ancient humans. If so, studying the populations could tell scientists whether today’s war on bacteria has eliminated some helping hands, organisms that once protected us all from allergies and autoimmune diseases.

To find out, Domínguez-Bello and her colleagues journeyed deep into the Amazon rainforest to the isolated village of Checherta, in Peru. There, her team collected DNA samples from villagers’ hands, feet, cheeks and tongue, as well as from air, livestock and work surfaces. By comparing these samples with similar ones collected in three other towns and cities—all in the Amazon, but with varying lifestyles—the team hopes to identify any microbe species that modern medicine may have wiped out.

Aliens Inside Us, a Smithsonian Channel documentary premiering May 4 at 8 p.m. ET, follows the research effort. As the scientists make contact, they also introduce antibiotics that could transform the microbiomes of the people in Checherta. It would be unethical, says Domínguez-Bello, to bring doctors to an area where people suffer from infectious diseases without offering help. “We spoil the very places we go for our study,” she says, ‘but it is unavoidable.”

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