Abstract: Atopic dermatitis (AD) is a chronic, inflammatory skin disease, primarily characterized by pruritus, dry skin, localized erythema, and scaling. It often coexists with allergic rhinitis and asthma, affecting approximately 5%–10% of adults and 15%–25% of children globally, with its incidence increasing annually. The pathogenesis of AD is complex, involving genetic factors, skin barrier dysfunction, immune dysregulation, and environmental factors. In recent years, studies have found that AD is closely related to the stability of gut microbiota: a reduction in gut microbial diversity and gut microbial dysbiosis may precede the onset of AD; dysbiosis of the gut microbiota can disrupt the gut barrier, trigger systemic immune responses, and exacerbate dermatitis symptoms. Probiotics, a low-side-effect therapy, can alleviate AD through multiple pathways. For instance, Lactiplantibacillus plantarum LM1004 has the ability to balance the Th1/Th2 immune response and regulate T-cell differentiation, thereby balancing immune responses; Lactobacillus paracasei KBL382 plays a positive role in regulating the intestinal microbiota, which in turn alleviates systemic inflammation; Bifidobacterium longum CCFM1029 can upregulate tryptophan metabolism to reduce the symptoms of atopic dermatitis; Lactobacillus sakei 65 can promote sebum production and repair impaired skin barrier. This review examines the intervening effects and mechanisms of probiotics on atopic dermatitis, highlighting that orally administered probiotics can alleviate the symptoms of atopic dermatitis by balancing systemic immunity, modulating microbiota structure, regulating metabolite secretion, and adjusting gene expression via the gut microbiota. Its aim is to provide a theoretical reference for the clinical treatment of atopic dermatitis.

Key words: atopic dermatitis; probiotics; immunity; intestinal microbiota