How leaky is the gut in Parkinson’s disease?
- Pascal Derkinderen, François Cossais, Kristína Kulcsárová, et al.
- 2025
Why this matters for your gut health
Parkinson’s disease (PD) is increasingly understood as a gut-brain axis disorder. The popular “Braak Hypothesis” suggests that a neurotropic pathogen enters through a porous gut lining, triggering the misfolding of $\alpha$-synuclein proteins that eventually travel to the brain. Confirming whether PD patients actually suffer from an impaired intestinal epithelial barrier (IEB)—or a “leaky gut”—is essential. If true, fixing the gut barrier could theoretically prevent or slow down the progression of the disease.
Summary
The review evaluates existing medical literature concerning intestinal permeability in Parkinson’s disease. It covers the organization of the intestinal barrier, the different paths molecules take across the gut lining, and critically analyzes the conflicting results from previous human trials. The authors point out that due to wildly inconsistent testing methodologies (e.g., distinct sugar probes, tissue staining techniques, and serum biomakers), it is too early to definitively label PD as a condition universally defined by a leaky gut. To fix this gap, they outline advanced diagnostic tools for future trials.
Key findings
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Diverging Experimental Results: Past studies on gut permeability in PD patients provide heavily conflicting conclusions. Some point to clear leaks, while others show no structural or functional difference compared to healthy controls.
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Methodological Inconsistencies: The divergence in scientific data stems from how researchers measured “leakiness”—ranging from oral sugar absorption tests to ex vivo mucosal tissue biopsies and varied blood biomarkers.
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Anatomical Variations: The paper outlines three core pathways through which gut barrier leakage can occur:
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Transcellular route: Directly across the cell membrane.
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Paracellular route: Through broken tight junctions (TJs) between epithelial cells.
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Non-specific route: Through macroscopic damage or areas of epithelial cell loss.
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The Path Forward: To resolve these conflicting results, the paper envisions and recommends adopting innovative, uniform diagnostic approaches, explicitly highlighting intestinal organoids (lab-grown mini-guts) and confocal laser endomicroscopy (real-time, microscopic imaging of the living gut wall).
Read the full paper
Citation
Derkinderen, P., Cossais, F., Kulcsárová, K., Škorvánek, M., Sellier-Montaigne, L., Coron, E., Leclair-Visonneau, L., Cerri, S., Pellegrini, C., & Rolli-Derkinderen, M. (2025). How leaky is the gut in Parkinson’s disease? eBioMedicine, 117, 105796.