P50 Metagenomic insights into gut microbiome dysbiosis and biomarker discovery in psoriasis

Abstract Psoriasis is a chronic inflammatory skin disease with an incompletely understood aetiology. Emerging evidence suggests a potential role of the gut microbiome in psoriasis pathogenesis, but existing studies have yielded inconsistent results. We performed shotgun metagenomic sequencing on faecal samples from 98 psoriasis patients and 45 healthy controls, including 28 patient-relative pairs. We found decreased species evenness in psoriasis patients, with lower alpha diversity indices compared with healthy controls. The disease status and living environment influenced microbiome composition. Notably, the microbiome composition of patient-relative controls was more similar to psoriasis patients than to non-familial healthy controls. We observed reduced interspecies interactions and increased localization in the gut microbial correlation network of psoriasis patients. Functional analysis identified altered microbial pathways, particularly those related to carbohydrate metabolism, nucleotide metabolism, and immune function. A poorly characterized species, s__GGB51647_SGB4348, was identified as a candidate biomarker for discriminating psoriasis by machine learning methods. Functionally, this species was enriched in carbohydrate and nucleotide metabolism pathways. In males, s__GGB51647_SGB4348 positively correlated with disease severity and CD4+ T-cell count. Collectively, these findings illuminate the multifaceted alterations in the gut microbiome associated with psoriasis and pave the way for novel diagnostic and therapeutic strategies targeting microbial dysbiosis.