Under researchGut-Brain Axis

Parkinson's Disease

A neurodegenerative disease in which GI symptoms often appear 10-20 years before motor impairments. The Braak hypothesis links the pathology to the gut. Human Biome already offers products for patients with Parkinson's disease.

Reviewed by:Dr. Zhang Wei·Gastroenterologist, Han's UnitedUpdated:March 12, 2026

What Is Parkinson's Disease?

A progressive neurodegenerative disease caused by the death of dopaminergic neurons in the substantia nigra of the brain.

About the Disease

Parkinson's disease affects approximately 1% of people over 60. It is characterized by the accumulation of alpha-synuclein and progressive neuron loss.

The Braak Hypothesis: The pathology may originate in the gut and spread to the brain via the vagus nerve. Alpha-synuclein is detected in the enteric nervous system long before motor symptoms appear.

Motor Symptoms

Resting tremor (hand trembling)
Muscle rigidity
Bradykinesia (slowness of movement)
Impaired balance and gait

Non-Motor Symptoms

Constipation -- often 10-20 years before diagnosis
Loss of smell (hyposmia)
Sleep disorders (REM phase)
Depression and anxiety
Cognitive impairment

Conventional Treatment

Levodopa, dopamine agonists, MAO-B inhibitors. Therapy is symptomatic -- it does not halt disease progression.

GI dysfunction affects levodopa absorption, reducing treatment efficacy. Restoring gut function may improve the response to therapy.

Why Fecal Microbiota Transplantation (FMT) for Parkinson's Disease?

The microbiome plays a key role in Parkinson's disease pathogenesis. FMT may target the root cause of the disease through the gut-brain axis.

Gut Dysbiosis

Decreased Prevotella, increased Akkermansia

Alpha-Synuclein in the Gut

Protein aggregation begins in the GI tract and spreads via the vagus nerve

FMT Transplantation

Restoration of a healthy microbiota

Potential Effect

Reduced inflammation, improved motility and levodopa absorption

The Microbiome–Parkinson's Connection

Patients with Parkinson's disease show characteristic microbiome changes: decreased Prevotella, increased Akkermansia, altered production of short-chain fatty acids and neuroactive substances. Human Biome already offers products for treating Parkinson's disease.

Potential Effects of FMT

Improved GI function (constipation, motility)
Reduced systemic inflammation
Improved levodopa absorption
Potential slowing of disease progression

Research Results

Clinical trials of FMT for Parkinson's disease demonstrate promising results. Han's United includes Parkinson's disease in its neurodegenerative disease practice.

UPDRS

Improvement in motor scores

10-20

Years before diagnosis -- GI symptoms

80%

Of Parkinson's patients with constipation

Phase II

Ongoing clinical trials

Key Studies

Scheperjans et al., Movement Disorders 2015: Characteristic microbiome changes identified in Parkinson's disease
Xue et al., Neurology 2020: FMT improved GI symptoms and motor scores in a pilot study
Human Biome: Offers specialized microbiota-based products for treating Parkinson's disease
Ongoing RCTs (2023-2026): Several Phase II trials underway in Europe and Asia

65%of patients report improvement

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Patient Story

Experience with FMT for Parkinson's Disease

"I was diagnosed 5 years ago. Constipation had been troubling me long before that. After a course of FMT, my bowel function significantly normalized, and levodopa started working more consistently. My overall well-being improved, with less fatigue. It's been a meaningful improvement in quality of life."

Zhang W.

67 years old, Nanchang

* Name changed. Results are individual and may vary.