The Role of Gut-Skin Axis in Acne Vulgaris Pathogenesis

Abstract

Introduction: Emerging evidence suggests that intestinal dysbiosis may influence systemic inflammation and sebaceous gland activity. This review synthesizes current knowledge on the gut-skin axis in acne vulgaris. Methods: A systematic literature search was conducted in PubMed, Scopus, and Web of Science for peer-reviewed articles published between 2015–2025, using terms "gut-skin axis," "acne," and "microbiome." After screening, 34 studies were included. Results: Acne patients exhibited lower gut microbial diversity, particularly reduced Bifidobacterium and Lactobacillus species. Elevated circulating lipopolysaccharides and inflammatory cytokines (IL-6, TNF-α) correlated with acne severity. Probiotic supplementation in four RCTs modestly reduced inflammatory lesion counts (mean reduction 32%). Discussion: The gut-skin axis likely operates through modulation of systemic inflammation, insulin-like growth factor-1, and sebum composition. Limitations include heterogeneity in probiotic strains and lack of long-term follow-up. Conclusions: Targeting gut microbiota may serve as an adjunctive acne therapy, though larger standardized trials are needed.