Microbiota–gut–skin axis. Bidirectional communication between the gut microbiota and skin occurs through bacterial metabolites, bacterial translocation, and immune system modulation, either by pathogens or probiotics. (a) Intestinal dysbiosis plays an important role in the inflammatory state of the skin in several dermatoses through the increase in proinflammatory metabolites, cytokines, and lymphocytes. (b) Probiotics help restore the balance through the increase in anti-inflammatory metabolites, such as SCFAs, immune cells, such as Treg lymphocytes, and cytokines, such as IL-10, to reduce and control the inflammation produced during these cutaneous pathologies: SCFAs, short-chain fatty acids; APC, antigen-presenting cell. Created with Biorender.com.