The skin microbiome and the gut-skin axis.

The microbiome plays a significant role in human health, homeostasis, immune system, and disease pathogenesis. Disrupted communication between the microbiome and host has been extensively studied in gastrointestinal diseases. To a lesser extent, there is emerging research on the skin microbiome and its connection with the gut, referred to as the gut-skin axis and its effects on dermatologic conditions. A basic overview will be provided of the gut and skin microbiome with a focus on the impact of this connection on cutaneous diseases, such as psoriasis, atopic dermatitis, rosacea, acne vulgaris, photoaging, and cutaneous wounds. In addition, we shall discuss nutrition-based approaches mediated through the gut-skin axis and topical treatments that could serve as potential adjunctive management by manipulation of the microbiome. In particular, there is a growing body of research on oral probiotics, prebiotics, and dietary modifications that may help improve symptoms for a variety of dermatologic conditions in select demographic groups.