In comparison

Microbiome scientists have peered into the guts of only a few populations around the world.

Here’s how the Yanomami gut stacks up against two other populations already studied: The Yanomami microbiome: The Yanomami have a microbiome diversity that is “unprecedented,” according to the new study. Their guts also have high levels of the bacterium Prevotella (commonly seen in traditional lifestyles and plantbased diets) and low Bacteroides, which tend to dominate Western guts. While the Yanomami are stunted (short for their age), they appear quite healthy with no obvious signs of obesity or metabolic diseases.

The Guahibo Amerindian microbiome (about 25 cent less diverse than the Yanomami):

Compared with the Yanomami, Venezuela’s Guahibo Amerindians have inched a few steps closer to westernization. Since the ’60s, many have moved into solid houses. While some still hunt and fish, others are now shopping for food like sugar, pasta and beer — and using antibiotics. Dominguez-Bello found that compared to the Yanomami, Guahibo Amerindians not only have less diversity but lower bacterial loads. They are also becoming overweight.

The American microbiome (about 50 per cent less diverse than the Yanomami):

In a 2012 study, Americans living in three U.S. cities had the least diversity in their gut microbiomes compared to the Guahibo Amerindians and rural Malawians. More than two thirds of Americans are also overweight or obese. Chronic diseases, like diabetes and heart disease, are skyrocketing. Scientists are noticing that in American guts, certain bacteria are vanishing; for example Helicobacter pylori — which causes gastric cancer but may also protect against childhood asthma and inflammatory bowel disease — populates the Yanomami microbiome but but not the American one.