Alterations of fecal microbiota and plasma metabolome in patients with Parkinson's disease with rapid eye movement sleep disorder

Objectives: Patients with Parkinson's disease (PD) with probable Rapid eye movement sleep Behavior Disorder (RBD) (PD-RBD), a specific subtype of PD, is characterized by the presence of more severe motor and non-motor symptoms. This study aimed to elucidate the characteristics and interactions of gut microbiota and plasma metabolic characteristics of PD-RBD, thus screening for the disease mechanisms.
Methods: A total of 100 PD patients, 50 healthy controls (HC) and 16 probable idiopathic RBD (iRBD) patients were collected. There were 33 PD-RBD and 67 patients without probable RBD (PD-nRBD) in PD patients. DNA extraction, PCR amplification and high-throughput sequencing were used for intestinal microbiota analysis and ultra-high liquid chromatography tandem mass spectrometry was used for metabolome analysis. Spearman analysis was applied to investigate the correlation of fecal microbiota and plasma metabolome.
Results: Our findings revealed Lactobacillaceae (P = 0.017), Christensenellaceae (P = 0.017), Fusobacteriaceae (P = 0.018), Lactobacillus (P = 0.035), Christensenellaceae R-7 group (P = 0.035) and Fusobacterium (P = 0.035) were significant different in PD-RBD, PD-nRBD and HC. Moreover, the differential metabolites identified in both PD-nRBD and PD-RBD were 3-Hydroxy-2-methylpyridine-4,5-dicarboxylate (VIP = 5.802) and 3-Methoxy-4-Hydroxyphenylglycol sulfate (VIP = 5.732). Furthermore, our analysis revealed that 3-Methoxy-4-Hydroxyphenylglycol sulfate showed a positive correlation with Lactobacillus (r = 0.197, P = 0.049). Finally, functional analysis indicated that these distinctive microbiota and metabolites were primarily associated with phenylalanine metabolism and vitamin B6 metabolism.
Conclusions: We managed to show that the differential microbiota, differential metabolites and their interactions in PD-RBD compared to PD-nRBD and HC. This furthers our understanding of disease pathogenesis, and offers fresh perspectives on its detection and treatment.