Yanomami skin microbiome complexity challenges prevailing concepts of healthy skin.

The adult skin microbiome typically exhibits low microbial complexity, particularly on sebaceous sites, where lipophilic Cutibacterium and Malassezia spp. predominate. Current understanding of healthy skin microbiome is largely based on western, industrialized populations, with limited representation of diverse cultures and lifestyles. Here, we investigate the skin microbiome of a remote indigenous Yanomami community and reveal a complex microbial ecosystem comprising 115 previously unreported bacterial genomes. The Yanomami skin microbiome includes genera common to western populations alongside diverse environmental taxa that form multiplex interactions with the dominant eukaryote Malassezia globosa. Functional profiling indicates that this microbiome supports skin homeostasis by fortifying barrier integrity through lipid metabolism and acid production and mitigating oxidative stress. Longitudinal monitoring of western expeditioner' skin demonstrates acquisition of the Yanomami microbiome following Amazonian immersion and its subsequent loss upon return to an industrialized setting. These findings reveal that diverse, environmentally enriched microbiota may confer skin benefits that are overlooked in current models of healthy skin.