Gut dysbiosis as a potential driver of Parkinson's and Alzheimer's disease pathogenesis.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing mechanistic and observational literature without systematic search or original data
PubMed 40880851 · doi:10.3389/fnins.2025.1600148
What was done
This narrative review integrates current published literature investigating how gut microbial dysbiosis may influence the pathogenesis of Alzheimer's disease (AD) and Parkinson's disease (PD). The authors summarize pathological mechanisms, examine differences in fecal bacterial taxa between AD/PD patients and healthy controls (specifically short-chain fatty acid [SCFA]-producing and lipopolysaccharide [LPS]-expressing bacteria), and detail hypothesized pathways connecting microbial metabolites to neuroinflammation, blood-brain barrier permeability, and neural propagation.
What was found
The abstract reports no quantitative figures, effect estimates, or sample sizes. Qualitatively, it reports that AD and PD patients exhibit altered fecal microbiota compared to controls, characterized by reductions in SCFA-producing bacteria and increases in LPS-expressing bacteria, which are hypothesized to promote systemic inflammation, protein misfolding, and disease progression.
Why it matters
It organizes current hypotheses on how the microbiome-gut-brain axis could influence neurodegeneration, highlighting potential avenues for biomarker development or personalized microbiome-targeted therapeutics.
Limits
As a narrative review, it synthesizes existing literature without systematic search criteria, quality appraisal, or meta-analytic pooling, and presents no new empirical data. The abstract provides no quantitative metrics, and causality between observed gut dysbiosis and neurodegenerative onset remains unestablished.
Cited by
- supports Increased gut permeability from dysbiosis allows messengers across the blood-brain barrier, making individuals more prone to neurodegenerative disorders like Parkinson's and Alzheimer's.