Alteration of the fecal microbiota in North-Eastern Han Chinese population with sporadic Parkinson’s disease Original paper

What was studied?

This review focuses on the alteration of fecal microbiota in Parkinson’s disease, examining how gut microbial shifts in North-Eastern Han Chinese adults with sporadic Parkinson’s disease (PD) compare with matched healthy controls. The study explored microbial composition using 16S rRNA gene sequencing, emphasizing how distinct taxa—including Verrucomicrobiaceae, Ruminococcaceae, Porphyromonadaceae, and Lachnospiraceae NK4A—differed significantly between groups. By integrating high-resolution sequencing and multivariate analyses, the authors aimed to clarify whether specific bacterial imbalances form microbiome signatures that might contribute to PD pathophysiology through mechanisms involving inflammation, gut permeability, short-chain fatty acid (SCFA) metabolism, and the gut–brain axis.

Who was studied?

The research examined fecal samples from 20 North-Eastern Han Chinese adults over age 65, including 10 individuals diagnosed with sporadic PD and 10 age- and sex-matched healthy controls. All participants met stringent inclusion and exclusion criteria designed to minimize confounding influences such as recent infections, antibiotic use, gastrointestinal disease, alcohol misuse, specific medications, and metabolic disorders. Clinical variables, including age, BMI, blood sugar, and blood pressure, showed no significant differences between groups, ensuring that microbial differences were unlikely to be explained by demographic or metabolic factors. Eight of the PD participants experienced constipation—an established early PD symptom—providing additional clinical context relevant to gut microbiome alterations.

Most important findings

The study identified notable gut microbiome differences at both the phylum and family levels. Healthy controls showed higher abundance of Bacteroidetes and Prevotellaceae, taxa linked to SCFA production, mucin synthesis, and maintenance of gut barrier integrity. In contrast, PD patients exhibited increased levels of Verrucomicrobiaceae (particularly Akkermansia muciniphila), Ruminococcaceae, Porphyromonadaceae, Pasteurellaceae, Hydrogenoanaerobacterium, and Lachnospiraceae NK4A. Many of these taxa contribute to altered fermentation profiles, increased gut permeability, or heightened inflammatory potential. LEfSe and Metastats analyses converged on the same set of discriminatory taxa, strengthening the evidence for PD-associated microbial signatures. Visualizations on pages 3–6, including the OTU Venn diagram and cladogram, demonstrated both reduced diversity and distinct clustering patterns in PD patients versus controls, reflecting a clear shift in gut ecological structure.

Key implications

These findings suggest that sporadic PD in this population is accompanied by characteristic microbial imbalances that may influence disease mechanisms. Reduced Prevotellaceae may impair SCFA-linked neuroprotection and compromise mucosal integrity, increasing susceptibility to endotoxin exposure and α-synuclein misfolding. Conversely, elevated Verrucomicrobiaceae and Ruminococcaceae may reflect compensatory metabolic activity or inflammatory stress, though their precise roles remain uncertain. Collectively, the altered taxa highlight potential microbiome biomarkers for PD risk stratification and contribute to growing evidence that gut dysbiosis may precede or exacerbate neurodegeneration. These microbial signatures may guide future therapeutic strategies targeting barrier integrity, SCFA pathways, or immunomodulation.

Citation

Li F, Wang P, Chen Z, et al. Alteration of the fecal microbiota in North-Eastern Han Chinese population with sporadic Parkinson’s disease.Neurosci Lett. 2019;707:134297. doi:10.1016/j.neulet.2019.134297