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Seven gut neuropeptides are dysregulated in Parkinson's disease and may drive gut-brain disease progression

RPEP-137892025Templeton, Hayley N; Tobet, Stuart A; Schwerdtfeger, Luke A
evidence
The takeaway

Dysregulation of 7 gut neuropeptides (VIP, NPY, CGRP, ghrelin, CCK, GLP-1, substance P) in the enteric nervous system may drive Parkinson's disease through gut-brain axis alterations linked to α-synuclein aggregation and neuroinflammation.

7 gut peptides dysregulated in PD

GI neuropeptide dysregulation may drive Parkinson's disease through the gut-brain axis, with symptoms preceding motor diagnosis by up to 20 years

What the researchers found

7 dysregulated gut neuropeptides in PD: VIP, NPY, CGRP, ghrelin, CCK, GLP-1, substance P. GI symptoms precede motor symptoms by up to 20 years. α-Synuclein aggregates in GI tract. Gut neuropeptides modulate: barrier function, immune response, gut-brain signaling. Underexplored research area.

Why it matters

PD may begin in the gut years before brain symptoms. Understanding how gut neuropeptides contribute to disease initiation and progression could enable early detection and intervention.

How the study worked

Narrative review of gut neuropeptide roles in PD pathogenesis, covering microbial metabolite and immune influences on neuropeptide signaling.

What this study cannot tell us

Narrative review. Mostly animal model evidence. Causation vs correlation unclear. Human gut neuropeptide data in PD limited.

How to read the evidence

Narrative review synthesizing animal and human evidence. Identifies important but underexplored research direction.

When this study was published

Published in 2025.

The bigger picture

If PD starts in the gut through neuropeptide dysregulation, targeting these peptides could prevent or slow disease progression before brain damage occurs—a paradigm shift from treating symptoms to preventing neurodegeneration.

Questions still open

  • Could gut neuropeptide levels serve as early PD biomarkers?
  • Would GLP-1 drugs protect against PD through gut neuropeptide modulation?
  • Is α-synuclein aggregation in the gut driven by specific neuropeptide dysregulation?

Common questions

Does Parkinson's disease start in the gut?
Growing evidence suggests it may. Gut symptoms often appear 20 years before Parkinson's is diagnosed, and the toxic protein (α-synuclein) that causes PD has been found in the GI tract. This review identifies 7 gut neuropeptides that are disrupted in PD and may facilitate disease spread from gut to brain.
Could testing gut hormones detect Parkinson's early?
Potentially. If specific gut neuropeptide patterns (VIP, NPY, CGRP, ghrelin, CCK, GLP-1, substance P) are altered years before motor symptoms, they could serve as early diagnostic biomarkers. GLP-1 drugs, already showing PD neuroprotection, might also work partly through restoring gut neuropeptide balance.

Read the original research

Gut neuropeptide involvement in Parkinson's disease.

American journal of physiology. Gastrointestinal and liver physiology, 328(6), G716-G733

View on PubMed ↗Publisher’s paper ↗

Citation

Templeton, Hayley N; Tobet, Stuart A; Schwerdtfeger, Luke A. (2025). Gut neuropeptide involvement in Parkinson's disease.. American journal of physiology. Gastrointestinal and liver physiology, 328(6), G716-G733. https://doi.org/10.1152/ajpgi.00383.2024