Fig. 1.

Skin microbiome, metabolome and skin phenome, from the perspective of skin as an ecosystem. From left to right: (Blue box) Diverse substances, derived from the host (stratum corneum, skin appendages, and plasma), environment (xenobiotics) and microbial metabolism, cover the skin surface, forming the micro-environment for skin microbiota; (Green box) occupation of ecological niches by self-adaptation and microbe–microbe interactions, promoting commensals or inhibiting pathogens; (Yellow box) the skin microbes, by their own structures or bioactive molecules, reshape the host skin phenotypes