Microbial diversity as a proxy for skin health: an ecological framework misapplied

The assumption that greater microbial diversity signals a healthier skin microbiome, now deeply embedded in clinical and research practice, represents a foundational category error. Drawing on decades of macroecological theory, we propose a three-tier framework distinguishing habitat conditions, community structure, and ecosystem services: taxonomic diversity reflects community structure alone, whereas skin health outcomes belong to the domain of ecosystem services. Applying this distinction rigorously offers a clearer lens through which microbiome data can be interpreted and intervention strategies more rationally designed.