PARKINSON DISEASE (Disorder)NCT07749261
Gut Microbiota and Tryptophan Metabolites in Parkinson's Disease
An observational study of PARKINSON DISEASE (Disorder), run by Ningxia Medical University at 1 site in China.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 45 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- PARKINSON DISEASE (Disorder)
- What is being tested?
- Stool Microbiome and Targeted Tryptophan Metabolite Profiling
- How many people
- 30 participants
- Where
- 1 siteChina
- Study dates
- 20 Aug 2026to 20 Nov 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Thirty participants will be enrolled in this single-center observational study, including 15 participants with Parkinson disease and 15 individually matched healthy controls. Participants with Parkinson disease will be recruited from neurology outpatient or inpatient services. Healthy controls may be recruited from health-screening programs, the community, or non-cohabiting relatives. Each healthy control will be matched to a participant with Parkinson disease by sex, age within 5 years, and body mass index within 3 kg/m^2. All participants will provide clinical and lifestyle information and one stool sample.
Who may be able to join
- 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
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
Laizhou People's Hospital
Laizhou, Shandong, 261400
Xiumei Gong, +8618553631703, 18553631703@163.com
About this study
Official title: 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.
- Conditions
- PARKINSON DISEASE (Disorder)
- Being tested
- Stool Microbiome and Targeted Tryptophan Metabolite Profiling
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Stool Microbiome and Targeted Tryptophan Metabolite ProfilingDiagnostic test
Each participant will provide one stool sample. Separate aliquots will be analyzed using 16S ribosomal RNA gene amplicon sequencing and targeted liquid chromatography-tandem mass spectrometry to characterize the gut microbiota and quantify prespecified tryptophan metabolites. These analyses are conducted for research purposes only and will not be used for clinical diagnosis or treatment decisions.
| Study group | Role | What they receive |
|---|---|---|
| Parkinson Disease Group | Participants aged 45 to 90 years with clinically established or clinically probable Parkinson disease. Participants will provide clinical and lifestyle information and one stool sample for 16S ribosomal RNA gene sequencing and targeted tryptophan metabolite analysis. No intervention will be assigned Receives: Diagnostic Test: Stool Microbiome and Targeted Tryptophan Metabolite Profiling | |
| Healthy Control Group | Healthy participants aged 45 to 90 years who are matched to the Parkinson disease group by sex, age, and body mass index. Participants will provide clinical and lifestyle information and one stool sample for 16S ribosomal RNA gene sequencing and targeted tryptophan metabolite analysis. No intervention will be assigned Receives: Diagnostic Test: Stool Microbiome and Targeted Tryptophan Metabolite Profiling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Between-Group Differences in Fecal Tryptophan Metabolite Concentrations
Fecal concentrations of tryptophan, kynurenine, kynurenic acid, quinolinic acid, indole-3-acetic acid, indole-3-lactic acid, indole-3-propionic acid, and tryptamine will be quantified using targeted liquid chromatography-tandem mass spectrometry. Results will be reported as nanograms per gram or micromoles per kilogram of wet stool. Matched between-group differences will be summarized using effect estimates, 95 percent confidence intervals, and Benjamini-Hochberg false discovery rate-adjusted results
Measured: At enrollment, based on one stool sample collected from each participant
Between-Group Difference in Fecal Microbial Community Structure
Fecal microbial community structure will be characterized using Bray-Curtis and Aitchison beta-diversity metrics derived from 16S ribosomal RNA gene amplicon sequencing. Differences between the Parkinson disease group and the matched healthy control group will be evaluated using permutational multivariate analysis of variance, with pair identification used to restrict permutations
Measured: At enrollment, based on one stool sample collected from each participant
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Aug 2026
- Study start20 Aug 2026 (estimated)
- Primary completion20 Oct 2026 (estimated)
- Study completion20 Nov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PARKINSON DISEASE (Disorder)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ningxia Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Hanqing Guo, Ningxia Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07749261
- Sponsor's protocol ID
- 2026-0570
- Status last verified
- Aug 2026
- First submitted
- 1 Aug 2026
- Last updated
- 6 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No public sharing of individual participant data is currently planned. Aggregate study results will be reported in scientific publications. Any future sharing of de-identified participant-level data would require confirmation of compatibility with participant consent, ethics approval, and an appropriate data-use agreement
Study at a glance
From the registry record, last updated by the sponsor on 6 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Exploratory Case-Control Study of Fecal Microbiota and Targeted Tryptophan Metabolite Profiling in Patients With Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07749261
- Acronym / sponsor ID
- 2026-0570
- Conditions
- PARKINSON DISEASE (Disorder)
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Ningxia Medical UniversityUniversity, hospital or other
- Study start
- 20 Aug 2026 (estimated)
- Primary completion
- 20 Oct 2026 (estimated)
- Study completion
- 20 Nov 2026 (estimated)
- First posted
- 6 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Parkinson Disease Group | – | Diagnostic Test: Stool Microbiome and Targeted Tryptophan Metabolite ProfilingParticipants aged 45 to 90 years with clinically established or clinically probable Parkinson disease. Participants will provide clinical and lifestyle information and one stool sample for 16S ribosomal RNA gene sequencing and targeted tryptophan metabolite analysis. No intervention will be assigned |
| Healthy Control Group | – | Diagnostic Test: Stool Microbiome and Targeted Tryptophan Metabolite ProfilingHealthy participants aged 45 to 90 years who are matched to the Parkinson disease group by sex, age, and body mass index. Participants will provide clinical and lifestyle information and one stool sample for 16S ribosomal RNA gene sequencing and targeted tryptophan metabolite analysis. No intervention will be assigned |
Who may qualify
- Ages
- 45 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Thirty participants will be enrolled in this single-center observational study, including 15 participants with Parkinson disease and 15 individually matched healthy controls. Participants with Parkinson disease will be recruited from neurology outpatient or inpatient services. Healthy controls may be recruited from health-screening programs, the community, or non-cohabiting relatives. Each healthy control will be matched to a participant with Parkinson disease by sex, age within 5 years, and body mass index within 3 kg/m^2. All participants will provide clinical and lifestyle information and one stool sample.
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (6 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Stool Microbiome and Targeted Tryptophan Metabolite ProfilingEach participant will provide one stool sample. Separate aliquots will be analyzed using 16S ribosomal RNA gene amplicon sequencing and targeted liquid chromatography-tandem mass spectrometry to characterize the gut microbiota and quantify prespecified tryptophan metabolites. These analyses are conducted for research purposes only and will not be used for clinical diagnosis or treatment decisions. | Diagnostic test | Healthy Control Group, Parkinson Disease Group |
Primary outcome
Between-Group Differences in Fecal Tryptophan Metabolite Concentrations
Time frame: At enrollment, based on one stool sample collected from each participant
Fecal concentrations of tryptophan, kynurenine, kynurenic acid, quinolinic acid, indole-3-acetic acid, indole-3-lactic acid, indole-3-propionic acid, and tryptamine will be quantified using targeted liquid chromatography-tandem mass spectrometry. Results will be reported as nanograms per gram or micromoles per kilogram of wet stool. Matched between-group differences will be summarized using effect estimates, 95 percent confidence intervals, and Benjamini-Hochberg false discovery rate-adjusted results
Between-Group Difference in Fecal Microbial Community Structure
Time frame: At enrollment, based on one stool sample collected from each participant
Fecal microbial community structure will be characterized using Bray-Curtis and Aitchison beta-diversity metrics derived from 16S ribosomal RNA gene amplicon sequencing. Differences between the Parkinson disease group and the matched healthy control group will be evaluated using permutational multivariate analysis of variance, with pair identification used to restrict permutations
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Aug 2026.
- Individual participant dataSharing planned: No. No public sharing of individual participant data is currently planned. Aggregate study results will be reported in scientific publications. Any future sharing of de-identified participant-level data would require confirmation of compatibility with participant consent, ethics approval, and an appropriate data-use agreement
Related trials for PARKINSON DISEASE (Disorder)
Not yet recruitingPhase 1/2
STAR0602 With Nivolumab in Non Small Cell Lung Cancer and in Metastatic Castrate-Resistant Prostate Cancer, and STAR0602 Alone in Thymic Carcinoma
NSCLC, Non-Small Cell Lung Cancer
Enrolling by invitationObservational study
Early Molecular Biomarkers for Differentiating Parkinsonian Syndromes
PARKINSON DISEASE (Disorder), Atypical Parkinsonism
RecruitingPhase 3
A Clinical Study of Sacituzumab Tirumotecan (MK-2870) in Combination With Pembrolizumab (MK-3475) as First-line Maintenance Treatment of Cervical Cancer (MK-2870-036/TroFuse-036/GOG-3123/ENGOT-cx22)
Cervical Cancer
Active, not recruitingPhase 1/2
Clinical Safety and Efficacy of Umbilical Cord Mesenchymal Stromal Cells-derived Exosomes in Patients With Parkinson's Disease
Parkinson Disease (PD)
Active, not recruitingObservational study
Adaptive DBS to Offset STN Dysregulation During Exercise in PD
Parkinson Disease
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of PARKINSON DISEASE (Disorder), run by Ningxia Medical University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 6 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact qinghan Guo (86+17753626689, ghqnxykd@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Between-Group Differences in Fecal Tryptophan Metabolite Concentrations (time frame: At enrollment, based on one stool sample collected from each participant). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Aug 2026.