Abstract
In patients with Parkinson's disease (PD), α-synuclein pathology is thought to spread to the brain via the dorsal motor nucleus of the vagus nerve. The link between the gut microbiome and PD has been explored in various studies. The appendix might play an important role in immunity by maintaining the microbiota as a reservoir. In recent times, appendectomy has been linked to a lower risk of PD, possibly owing to the role of the appendix in altering the gut microbiome. We aimed to elucidate whether the gut microbiota affects PD development in the appendectomy cohort. We analyzed the fecal microbial composition in patients with PD and healthy controls with and without a history of appendectomy. The abundance of microbes from the family Enterobacteriaceae was higher in feces samples from patients with Parkinson's disease compared to that in samples collected from healthy controls. Furthermore, there was a significant phylogenetic difference between patients with PD and healthy controls who had undergone appendectomy. There was a significant phylogenetic difference between patients with PD and HCs who had undergone APP. These results suggest the correlation between gut microbiota and PD in patients who have undergone APP.