The study of the human microbiome—the motley assortment of microbes that live in our bodies—has largely been the study of the Western microbiome. The research has been heavily biased towards people from Europe, North America, and other WEIRD countries—that is, Western, Educated, Industrialised, Rich and Democratic. It’s like trying to understand how cities work by studying London and New York, and ignoring Mumbai, Mexico City, Sao Paulo, Cairo, and others.

Recognising this problem, scientists are starting to catalogue the microbes of rural populations, including hunter-gatherers. Early last year, I wrote about attempts by Maria Gloria Dominguez-Bello and Cecil Lewis Jr to study the microbiomes of the Yanomami of Venezuela and the Matses of Peru, respectively. A few months later, I