Wilson's disease (WD), an autosomal recessive disorder causing copper accumulation in vital organs, affects approximately 0.03-0.02% of the population globally. Pathogenic mutations in the *ATP7B* gene disrupt copper transport, leading to excess biliary excretion. Emerging evidence links gut microbiome dysbiosis to various diseases, including genetic and metabolic disorders. Given the role of environmental and dietary factors in modifying gene expression in WD, and the use of penicillamine (a copper-chelating agent derived from penicillin and potentially influenced by microbiota) in WD treatment, this study investigated the potential correlation between WD and gut microbiome composition. Understanding this interaction could lead to novel therapeutic strategies for WD.

Previous studies have indicated a link between gut microbiome dysbiosis and various diseases. A study by Geng et al. explored the gut microbiome in WD patients, reporting disruption of equilibrium, reduced diversity, and altered composition at the phylum level. However, detailed characterizations at different taxonomic levels were lacking. Other studies highlight the gut microbiome's involvement in nutrient metabolism, immune system development, and the prevention of infections. The impact of genetic predisposition on the gut microbiome is also recognized, especially concerning autoimmunity. Given the complexity of WD, research on the gut microbiome’s role is essential for developing new treatment strategies.

Fecal samples were collected from 14 newly diagnosed WD patients and 16 healthy controls. 16S rRNA sequencing of the V4 region was performed to analyze the gut microbiome composition. Alpha diversity indices (Shannon, Simpson, Observed, ACE, Chao1, J) were calculated to assess diversity. Beta diversity was analyzed using NMDS, ANOSIM, PCA, and PCoA based on Bray-Curtis and UniFrac distances. KEGG and COG pathway analyses were conducted using PICRUSt to compare functional profiles. Statistical analyses included Wilcoxon's rank-sum test, Fisher's exact test, and chi-square test, with significance set at P<0.05.

Compared to healthy controls, the WD group showed significantly lower alpha diversity (Shannon and Simpson indices). Beta diversity analysis revealed distinct clustering of WD patients' gut microbiota from the controls. At the phylum level, WD patients had significantly lower abundance of Actinobacteria, Firmicutes, and Verrucomicrobia, and higher abundance of Bacteroidetes, Proteobacteria, Cyanobacteria, and Fusobacteria. The Firmicutes/Bacteroidetes ratio was also significantly lower in the WD group. At the family and genus levels, several taxa showed significant differences, including increased *Bacteroides* and *Enterobacteriaceae* and decreased *Blautia*, *Ruminococcus*, and *Coprococcus*. Functional analysis (KEGG and COG) revealed reduced abundance of pathways related to transcription factors, ABC-type transporters, and various metabolic pathways in the WD group.

This study provides detailed insights into gut microbiota dysbiosis in WD patients, extending previous findings by Geng et al. The lower abundance of butyrate-producing bacteria (Firmicutes) and mucin-degrading bacteria (Verrucomicrobia) could contribute to impaired intestinal function and inflammation. The increased abundance of opportunistic pathogens (Proteobacteria, Fusobacteria) suggests a potential role in disease pathogenesis. The reduced abundance of transport and metabolic pathways supports the hypothesis that gut microbiota dysfunction affects WD's metabolic processes. The lower Firmicutes/Bacteroidetes ratio may contribute to reduced SCFA production and altered immune responses. The study suggests that targeting specific bacterial biomarkers or metabolites could lead to new treatment strategies, such as fecal microbiota transplantation or SCFA supplementation.

This study demonstrates significant alterations in gut microbiota diversity and composition in WD patients, suggesting a potential role in WD pathogenesis. The identified changes in specific bacterial taxa and metabolic pathways warrant further investigation to explore potential therapeutic interventions, such as fecal microbiota transplantation or targeted metabolite supplementation. Further research with larger sample sizes and metagenomic/metabolomic analyses is necessary to confirm these findings and identify specific microbial biomarkers for WD.

The relatively small sample size is a limitation that could affect the generalizability of the results. Further studies with larger, more diverse cohorts are needed to validate these findings. The study relied on 16S rRNA sequencing, which does not provide complete information about functional capacity. Future research using metagenomic and metabolomic approaches could provide more comprehensive insights into the gut microbiome's role in WD.