Altered gut microbiota in Parkinson’s disease patients/healthy spouses and its association with clinical features Original paper

What was studied?

Altered gut microbiota in Parkinson’s disease was examined using 16S rRNA sequencing to determine how microbial composition differs among patients, their healthy spouses, and unrelated healthy controls. The study analyzed 200 individuals and evaluated microbial diversity, specific bacterial taxa, and associations with clinical severity measured by Hoehn & Yahr staging and disease duration. It also explored whether shared environments shape the gut microbiome, particularly within patient–spouse pairs. Images on page 3 further illustrate distinct clustering patterns among groups and highlight significantly altered genera.

Who was studied?

The cohort included 63 individuals with Parkinson’s disease, 63 of their healthy spouses, and 74 unrelated healthy participants. All subjects were age-matched, and demographic similarity minimized confounding effects from age or sex. Patients represented varying stages and durations of disease, allowing microbial patterns to be mapped across progression. The inclusion of spouses provided a rare opportunity to isolate environmental influences on microbiome structure.

Most important findings

Microbial diversity was significantly higher in Parkinson’s disease than in both healthy groups, as shown in alpha diversity plots on page 3. Beta diversity analyses demonstrated clear separation between patients and controls, signaling substantial compositional shifts. Several phyla—including Firmicutes, Actinobacteria, and Verrucomicrobia—were enriched in Parkinson’s disease, whereas Bacteroidetes and Fusobacteria were reduced. At the genus level, Oscillospira and Akkermansia were markedly elevated in Parkinson’s disease, while Fusobacterium was reduced. Crucially, the study identified eight genera consistently increasing with both higher Hoehn & Yahr stages and longer disease duration: Parabacteroides, Akkermansia, Coprococcus, Bilophila, Collinsella, Methanobrevibacter, Eggerthella, and Adlercreutzia. These trends, displayed in the progression scatterplots on page 3, point toward inflammation-linked microbial signatures associated with worsening disease. A panel of seven genera also distinguished patients from healthy controls with an AUC of 0.856, suggesting potential diagnostic utility.

Interesting environmental effects emerged: spouses exhibited lower diversity than unrelated controls and shared specific shifts in genera such as Prevotella, indicating microbiome convergence within households.

Key implications

The findings underscore a robust association between gut dysbiosis and Parkinson’s disease, highlighting inflammatory genera that may influence neurodegeneration through mucosal permeability, immune activation, or metabolite disruption. The repeated appearance of taxa such as Akkermansia and Bilophila supports models of gut-originating inflammatory cascades contributing to α-synuclein pathology. The ability of a small microbial panel to differentiate patients from controls suggests the possible development of gut-based biomarkers. Moreover, the environmental influence detected in spouses’ signals that future research and clinical interpretation must account for shared diet and lifestyle. Collectively, the data illuminate microbial signatures with potential relevance to therapeutic strategies such as microbiota-directed interventions or fecal microbial transplantation targeting inflammation-linked genera.

Citation

Zhang F, Yue L, Fang X, et al. Altered gut microbiota in Parkinson’s disease patients/healthy spouses and its association with clinical features. Parkinsonism Relat Disord. 2020;81:84-88