Comparing gut bacteria and tryptophan byproducts in people with and without Parkinson's disease
Compares stool samples from 15 people with Parkinson's disease and 15 healthy people.
Plain-language title generated from the registry record
Registry title: Gut Microbiota and Tryptophan Metabolites in Parkinson's Disease
Key facts
- Where
- Laizhou, ChinaSee the site
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 45 and 90 years old?
Source: NCT07749261, who can take part
Where in China
- Laizhou People's HospitalLaizhou, ChinaNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Ningxia Medical University
- Trial code
- NCT07749261
- Record updated
- 6 August 2026
- Original description
Parkinson's disease is a progressive neurological disorder that can also affect the digestive system. Changes in gut microorganisms and tryptophan metabolites may be associated with Parkinson's disease, but these relationships are not fully understood. This exploratory observational study will compare gut microbial communities and targeted tryptophan metabolite profiles between 15 participants with Parkinson's disease and 15 healthy controls matched by sex, age, and body mass index.Read full original descriptionShow less
An Exploratory Case-Control Study of Fecal Microbiota and Targeted Tryptophan Metabolite Profiling in Patients With Parkinson's Disease
Parkinson's disease is a progressive neurological disorder that can also affect the digestive system. Changes in gut microorganisms and tryptophan metabolites may be associated with Parkinson's disease, but these relationships are not fully understood. This exploratory observational study will compare gut microbial communities and targeted tryptophan metabolite profiles between 15 participants with Parkinson's disease and 15 healthy controls matched by sex, age, and body mass index.
Each participant will provide clinical and lifestyle information and one stool sample. Stool samples will be analyzed using 16S ribosomal RNA gene sequencing and targeted liquid chromatography-tandem mass spectrometry. The study will evaluate differences in gut microbial composition and selected tryptophan metabolites and explore their associations with constipation, bowel habits, medication use, and clinical features of Parkinson's disease. No treatment will be assigned, and participants' usual medical care will not be changed. The findings are exploratory and are intended to guide larger future studies; they cannot establish causality or be used to diagnose Parkinson's disease.
Inclusion: Participants aged 45 to 90 years, of any sex. Participants able to understand the study, provide written informed consent, and provide an acceptable stool sample according to the study procedures; For the Parkinson disease group: clinically established or clinically probable Parkinson disease diagnosed by a neurologist according to the Movement Disorder Society Clinical Diagnostic Criteria; For the Parkinson disease group: preferably a disease duration of 5 years or less and Hoehn-Yahr stage I to III; For the Parkinson disease group: stable antiparkinsonian medication regimen for at least 4 weeks before enrollment; For the healthy control group: no history of Parkinson disease, parkinsonism, or another neurodegenerative disorder and no evident parkinsonian symptoms at screening; Healthy controls matched individually to participants with Parkinson disease by sex, age within 5 years, and body mass index within 3 kg/m\^2.
Exclusion: Use of systemic antibiotics within 3 months before stool collection. Use of probiotics, prebiotics, tryptophan, 5-hydroxytryptophan, live biotherapeutic products, or other microbiome-related supplements within 4 weeks before stool collection; Acute infection, fever, acute diarrhea, gastroenteritis, colonoscopy preparation, or a major dietary change within 4 weeks before stool collection; Active inflammatory bowel disease, celiac disease, short-bowel syndrome, gastrointestinal malignancy, or major gastrointestinal surgery within 6 months; Active cancer, decompensated liver or kidney disease, severe cardiovascular or hematological disease, active autoimmune disease, or current systemic glucocorticoid or immunosuppressive treatment; Pregnancy or breastfeeding. Long-term exclusive enteral or parenteral nutrition. Inability to provide an acceptable stool sample or essential clinical information; Any other condition considered by the investigator to compromise participant safety, study adherence, or interpretation of the results.