Therapeutic potential of polygonatum polysaccharides in modulating gut microbiota and alleviating psoriasis-like inflammation in a mouse model.

Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation and immune dysregulation. The gut microbiota has emerged as a significant factor influencing the pathogenesis of psoriasis, particularly through the gut-skin axis. This study investigates the therapeutic effects of Polygonatum polysaccharides (PSP) on imiquimod (IMQ)-induced psoriasis-like dermatitis in mice, focusing on gut microbiota modulation and systemic immune responses. Mice were treated with varying doses of PSP, and their effects were compared to methotrexate (MTX) as a positive control. PSP treatment significantly alleviated psoriasis-like skin inflammation, as evidenced by reduced epidermal hyperplasia, lower the modified Psoriasis Area and Severity Index (PASI) scores, and decreased levels of pro-inflammatory cytokines. Moreover, PSP restored gut microbial diversity and altered the composition of key bacterial taxa, notably reducing the abundance of Oscillibacter and Ruminiclostridium 9, which are associated with psoriasis severity. Functional predictions revealed that PSP modulates metabolic and immune-related pathways, potentially suppressing pro-inflammatory processes. These findings suggest that PSP exerts its therapeutic effects by targeting both the skin and gut microbiota, offering a promising multi-targeted approach for psoriasis treatment.