PARKINSON DISEASE (Disorder)
Conditions
Brief 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. 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.
Interventions
DIAGNOSTIC_TESTStool Microbiome and Targeted Tryptophan Metabolite Profiling
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.
Sponsors
Ningxia Medical University
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
45 Years to 90 Years
Healthy volunteers
Yes
Inclusion criteria
* 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 criteria
* 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Between-Group Differences in Fecal Tryptophan Metabolite Concentrations | 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 | 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 |
Countries
China
Contacts
CONTACTqinghan Guo
Outcome results
None listed