Industrialization increases the estrogen-recycling capacity of the gut microbiome

, 324-335 (2011)]. To date, it is not known if populations differ in this microbial function, and little is known about its determinants. Here we analyze estrobolomes using publicly available gut microbiome data from 24 populations spanning four continents and subsistence modes ranging from hunting and gathering to pastoralism, rural farming, and industrialized agriculture. We show that industrialized populations exhibit up to seven times greater estrogen-recycling capacity and nearly twofold higher estrobolome diversity compared with nonindustrial groups. We further find that formula-fed infants display two- to threefold higher recycling capacity and as much as eleven times greater estrobolome diversity than breastfed counterparts, revealing early-life divergence in microbial estrogen metabolism. By contrast, sex, age, and BMI are not associated with estrobolome characteristics. These findings demonstrate the crucial impact of industrialized lifestyles, including formula feeding, on the microbial capacity to influence systemic estrogen levels, with implications for life history, reproductive biology, and estrogen-associated diseases, including cancer.