[Features of gut microbiota in patients with idiopathic Parkinson's disease]

Objectives: To investigate whether the fecal microbiome of Parkinson's disease patients differs from that of healthy population and explore the pathogenesis and new treatment of idiopathic Parkinson's disease. Methods: A total of 30 patients diagnosed as idiopathic Parkinson disease (PD group) in Beijing Friendship Hospital between April 2017 and June 2018 were enrolled and 30 healthy controls (NC group) were recruited at the same time.Medical records and score of unified Parkinson's disease rating scale (UPDRS) were collected and fresh fecal samples were obtained and stored in refrigerator (-80℃). The microbial compositions of fecal samples were investigated by 16S rRNA gene sequencing targeting the V3-V4 region. The taxa abundance and microbial composition were tested. Results: There was no difference of age and sex in PD and NC groups. Chao1 and Shannon indexes tended to be higher in PD group, yet failed to reach statistic significance (P=0.115 and 0.052). Relative abundance of gut microbiota differed in each taxonomic category. The relative abundance of Firmicutes in PD group was 53.6%(41.7%-64.8%), while that of Bacteroidetes in NC group was 51.7%(31.7%-65.3%). The ratios of Firmicutes to Bacteroidetes were significantly different between the two groups (1.6(0.9-3.4) vs 0.7(0.5-1.4), P=0.001). In Clostridia, Bacilli and Erysipelotrichia of Firmicutes, the relative abundances of Clostridiales, Christensenellaceae, Peptoclostridium, Lactobacillus and Erysipelatoclostridium were higher in PD group (P=0.024, 0.046, 0.036, 0.022 and 0.037). The relative abundance of Prevotella of Bacteroidales, was lower in PD group, yet failed to reach statistic significance (P=0.121). The relative abundances of Alistipes of Rikenellaceae and Butyricimonas of Marinilabiliales in PD group were significantly higher than those in NC group (P=0.047 and 0.033). The relative abundance of Bifidobacterium of Actinobacteria was significanly higher in PD group when compared with NC group (P=0.009). Despite the relatively low abundance, Akkermansia of Verrucomicrobia was significantly higher in PD group than in NC group (P=0.025). Conclusion: The structures of the fecal microbiota differ significantly between PD patients and healthy controls.