Analysis of Gut Microbiota in Patients with Parkinson’s Disease Original paper

What was studied?

This study investigated gut microbiota in Parkinson’s disease using 16S rRNA sequencing to characterize microbial alterations linked to neurodegeneration. Fecal samples underwent high-throughput sequencing of the V3–V4 regions, with taxonomic assignment performed using QIIME and HITdb. The researchers aimed to identify Parkinson’s specific microbial signatures that might influence α-synuclein aggregation, inflammation, or disease progression. Figures on pages 2 and 3 illustrate reduced microbial diversity in Parkinson’s patients and clear clustering differences between disease and control groups, indicating distinct community structures.

Who was studied?

The study analyzed 89 individuals diagnosed with Parkinson’s disease and 66 healthy controls without Parkinsonian symptoms. Groups were well-matched in age and BMI, minimizing confounding by these variables. All participants underwent standardized clinical assessments, and stool samples were collected under uniform conditions.

Most important findings

Parkinson’s patients exhibited significantly reduced microbial diversity compared with controls, a pattern often associated with low-grade intestinal inflammation. Beta-diversity analysis revealed distinct microbial community separation. At the genus level, Parkinson’s patients showed increased Christensenella, Catabacter, Lactobacillus, Oscillospira, and Bifidobacterium, while controls had more Dorea, Bacteroides, Prevotella, and Faecalibacterium. The bar charts on page 3 highlight these shifts visually. At the species level, elevated taxa in Parkinson’s included Christensenella minuta, Catabacter hongkongensis, Lactobacillus mucosae, Ruminococcus bromii, and Papillibacter cinnamivorans. Control samples contained more Bacteroides massiliensis, Stoquefichus massiliensis, Bacteroides coprocola, Blautia glucerasea, Dorea longicatena, Bacteroides dorei, Bacteroides plebeus, Prevotella copri, Coprococcus eutactus, and Ruminococcus callidus.

These microbial changes are biologically relevant. Christensenellaceae are strongly heritable and linked to low BMI, aligning with common weight loss in Parkinson’s. Increased Lactobacillus may influence α-synuclein secretion through gut–neuron interactions. Reduced SCFA-producing taxa such as Faecalibacterium, Prevotella, and Dorea suggest impaired anti-inflammatory capacity, potentially contributing to α-synuclein misfolding.

Key implications

The study supports a mechanistic link between gut dysbiosis and Parkinson’s pathophysiology, highlighting microbial communities capable of modulating inflammation, barrier integrity, and neuronal signaling. The distinct set of depleted SCFA producers and expanded proinflammatory or metabolically active genera may represent a clinically useful microbiome signature. Such taxa could serve as biomarkers for early detection or targets for microbiome-directed therapies, including dietary modulation, probiotics, or next-generation microbial interventions.

Citation

Petrov VA, Saltykova IV, Zhukova IA, et al. Analysis of gut microbiota in patients with Parkinson’s disease. Bulletin of Experimental Biology and Medicine. 2017;162(6):734-737. doi:10.1007/s10517-017-3700-7