The skin-gut axis

The skin-gut axis represents a complex, bidirectional communication network where environmental triggers on the skin can directly modulate the gastrointestinal environment. Pioneering research has demonstrated that skin exposure to Narrow-Band Ultraviolet B (NB-UVB) light directly alters the human gut microbiome composition and increases its biodiversity, establishing a novel systemic pathway through which sunlight affects metabolic and immunological health.