Psoriasis severity links to elevated fecal IL-12p70, IL-1α, and altered gut microbiome.

Psoriasis is a chronic inflammatory skin condition driven by complex immune dysregulation, often involving T-helper 17 (Th17) and Th1 pathways. Current treatments target specific inflammatory mediators, but understanding the broader systemic factors, particularly the gut-skin axis, remains crucial for comprehensive management. The gut microbiome is increasingly recognized as a key modulator of systemic immunity, and its alterations (dysbiosis) are implicated in various inflammatory diseases. This study aimed to elucidate the specific relationships between gut microbial diversity, fecal cytokine profiles, and disease severity in psoriasis patients, addressing a gap in understanding this intricate interplay.

This observational study enrolled 91 patients with mild-to-moderate psoriasis and 92 nominally healthy volunteers as controls. Disease severity was quantified using the Psoriasis Area and Severity Index (PASI). Fecal samples underwent multiplex analysis to profile a panel of inflammatory mediators, including IL-1α, IL-4, IL-6, IL-8, IL-12p70, IL-17, IFN-γ, and TNF-α. Gut microbiome composition was characterized via 16S rRNA gene sequencing. Microbial diversity was assessed using alpha-diversity indices (Shannon, Simpson) and beta-diversity measures (Bray-Curtis dissimilarity, principal coordinates analysis).

Patients with psoriasis exhibited significantly elevated levels of pro-inflammatory cytokines in fecal samples compared to healthy controls. The most pronounced increases were observed in IL-12p70 and IL-1α. Statistical analysis revealed significant positive correlations between PASI scores and the levels of IL-4, IL-8, and EGF, suggesting these immune markers track with disease severity. Beta-diversity analysis indicated a trend toward differences in microbial community structure between the psoriasis and control groups; however, these findings were not statistically confirmed by PERMANOVA. Additionally, the study identified differences in the relative abundance of specific bacterial taxa, though the abstract did not detail which ones. These findings collectively underscore a clear link between immune dysregulation, gut microbiota composition, and disease severity in psoriasis.

The most pronounced increases in fecal cytokines in psoriasis patients were observed in IL-12p70 and IL-1α, highlighting their potential role in disease pathogenesis.