Gut Microbiota and Metabolome Alterations Associated with Parkinson’s Disease Original paper

What was studied?

The study Gut microbiota and metabolome alterations associated with Parkinson’s disease examined how the Parkinson’s disease gut microbiota and metabolome differ from those of healthy individuals. Using 16S rRNA sequencing and gas chromatography–mass spectrometry, the authors analyzed fecal samples to define microbe–metabolite signatures that connect intestinal dysbiosis to Parkinson’s pathology. This combined profiling allowed researchers to characterize bacterial taxa shifts, evaluate short-chain fatty acid (SCFA)–producing taxa, and map metabolic abnormalities in amino acids, vitamins, lipids, and polyamines. The integration of microbiome and metabolome analyses creates a detailed picture of gut-derived biochemical imbalances linked to neuroinflammation, energy deficits, and perturbations in host–microbe crosstalk relevant to PD pathogenesis.

Who was studied?

The study assessed 64 Italian adults with idiopathic Parkinson’s disease and 51 healthy controls matched primarily through family or spousal relationships. PD participants ranged from Hoehn and Yahr stages I–IV and were receiving stable dopaminergic therapy. Exclusion criteria ensured removal of confounders such as recent antibiotic or probiotic use, active gastrointestinal disease, or major psychiatric or neurological comorbidities. Control subjects reported no constipation and were free of neurological disorders. This well-defined clinical cohort provided a robust framework to analyze gut microbial composition and fecal metabolites across disease and non-disease groups.

Most important findings

PD patients exhibited major depletion of SCFA-producing genera—Lachnospira, Blautia, Butyrivibrio, Roseburia, Coprococcus, and Pseudobutyrivibrio—as clearly visible in the taxonomic heat maps. These taxa, primarily within Lachnospiraceae, are known contributors to gut barrier integrity, anti-inflammatory signaling, and metabolic homeostasis. Concurrent enrichment of Akkermansia, Veillonella, Streptococcus, Escherichia, Enterobacter, Serratia, and Bifidobacterium indicated a community shift toward organisms associated with mucin degradation, lactate accumulation, and increased endotoxin potential. Metabolomics revealed elevated cadaverine, ethanolamine, hydroxypropionic acid, phenylalanine, leucine, isoleucine, and thymine, while linoleic acid, oleic acid, succinic acid, nicotinic acid, pantothenic acid, and pyroglutamic acid were markedly decreased. Correlation matrices showed strong positive associations between Lachnospira-related genera and vitamins B3 and B5, highlighting microbial contributions to micronutrient availability.

Key implications

Findings support the concept that PD involves a gut-based disruption of SCFA production, vitamin biosynthesis, lipid metabolism, and amino acid turnover. Reduced SCFA-producing taxa may impair motility, gut barrier stability, and immune modulation, while diminished B-vitamin–linked pathways suggest compromised microbial nutrient synthesis with implications for mitochondrial energy deficits and oxidative stress. These integrated microbial–metabolite signatures may serve as biomarkers for PD risk stratification, disease progression, or therapeutic targeting.

Citation

Vascellari S, Palmas V, Melis M, Pisanu S, Cusano R, Uva P, et al. Gut microbiota and metabolome alterations associated with Parkinson’s disease.mSystems. 2020;5(5):e00561-20. doi:10.1128/mSystems.00561-20