Emerging mechanisms of microplastic-induced skin diseases: a perspective from the gut–skin axis

Microplastics (MPs), ubiquitous environmental pollutants, can enter the human body through ingestion, inhalation, and dermal contact, accumulate in various organs, and exert harmful effects. Emerging evidence suggests that both the skin and the gut serve as key immunological and neuroendocrine organs, sharing structural and neuroanatomical similarities. The interaction between these two systems is referred to as the "gut-skin axis." Numerous studies have demonstrated that MPs not only induce gut microbiota dysbiosis and compromise intestinal barrier integrity but also impair skin barrier function. Thus, the gut-skin axis offers a novel perspective for understanding MP-induced toxicity. Although interactions between MPs and the gut-skin axis have garnered increasing scientific interest, the mechanistic understanding of how MPs may mediate crosstalk between the gut and skin remains limited, and the impact of MPs on skin damage is not yet fully elucidated. MPs can directly disrupt gut microbial homeostasis and epithelial barrier function, allowing harmful bacteria and microbial metabolites to translocate into the bloodstream and exert systemic effects, ultimately contributing to cutaneous inflammation, metabolic imbalance, and oxidative stress. This review summarizes the mechanisms by which MPs exposure induces gut microbiota dysbiosis and skin damage from an integrated gut-skin axis perspective, highlighting their interplay's relevance. Understanding changes in gut microbiota and its metabolites may represent a promising approach to mitigate MP-induced skin diseases via modulation of the gut-skin axis.