High levels of are associated with the pathogenesis of Parkinson's disease.

Background: The diagnosis of Parkinson's disease (PD) is complex and there are no biomarkers for early identification. Many studies have reported altered gut microbiota in patients with PD compared with healthy individuals. However, results from previous studies vary across countries.

Aims: The aim of this study was to identify gut microbiota biomarkers that could be used as a marker for the diagnosis of PD.

Methods: Firstly, the differential gut microbiota was obtained by meta-analysis, and then the results of meta-analysis were validated through metagenomic cohort. Finally, the ROC curve was drawn based on the metagenomic validation results.

Results: The meta-analysis showed a lower relative abundance of ( < 0.00001) and ( = 0.002), and a higher of ( < 0.00001), ( = 0.03), ( < 0.00001), and ( = 0.02) in patients with PD. Only was also at high levels in the validation cohort of the metagenome. Meanwhile, three species from the , including ( = 0.022), ( = 0.005), and ( = 0.024) were also high. The ROC curve showed that the three species (71.2%) from had good predictive efficiency for PD.

Conclusion: Elevated may be associated with PD. Elevated three species from the , including , and may provide new potential biomarkers for the diagnosis of PD.