How PEG bowel preparation affects gut bacteria in people with or without an appendix
Impact of Polyethylene Glycol (PEG) Bowel Preparation on Intestinal Microbiota Composition and Diversity in Patients Undergoing Appendectomy
This observational study will test whether polyethylene glycol colonoscopy prep changes gut bacteria differently in adults who have had an appendectomy compared with those who have not.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 10 (estimated) |
| Ages | 18 Years to 75 Years |
| Sex | All |
| Sponsor | Tongji Hospital Academic / other |
| Locations | 1 site (Wuhan, Hubei) |
| Trial ID | NCT07478029 on ClinicalTrials.gov |
What this trial studies
This single-center observational study at Tongji Hospital will enroll adults aged 18–75 undergoing colonoscopy and group them by prior appendectomy (or right hemicolectomy) versus intact appendix. Participants will receive standard PEG bowel preparation and provide stool samples before and after the prep for microbiome analysis. The study will compare changes in microbial diversity, shifts in key taxa, and related metabolic markers between the groups while excluding recent antibiotic users and those with major comorbidities or colonoscopy contraindications. The aim is to determine whether the appendix influences microbiome disruption or recovery after PEG bowel cleansing.
Who should consider this trial
Good fit: Adults 18–75 years old who are scheduled for colonoscopy, generally healthy, have not used antibiotics in the prior six months, and either have a history of appendectomy/right hemicolectomy or have an intact appendix.
Not a fit: People who recently took antibiotics, are pregnant or breastfeeding, have major organ disease or contraindications to colonoscopy, or have significant mental disorders are unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, the findings could clarify whether appendectomy modifies PEG's effects on the gut microbiome and help inform safer colonoscopy preparation practices.
How similar studies have performed: Previous research has shown that PEG bowel preparation produces acute changes in gut microbial diversity and composition, but long-term effects and the specific protective or reservoir role of the appendix remain underexplored.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Aged 18-75 years. * Scheduled to undergo colonoscopy. * Generally healthy without major organ diseases. 1. For appendectomy group: history of appendectomy or right hemicolectomy (including appendectomy). 2. For control group: no history of appendectomy or right hemicolectomy. Exclusion Criteria: * Allergy or intolerance to PEG laxatives. * Pregnant or lactating women. * Mental disorders. * Use of antibiotics within 6 months prior to study enrollment. 1. Contraindications to colonoscopy (e.g., severe cardiopulmonary insufficiency). 2. For control group only: presence of organic diseases.
Where this trial is running
Wuhan, Hubei
- Department of Gastroenterology Tongji Hospital, Tongji Medical college, Huazhong University of Science and technology — Wuhan, Hubei, China (Recruiting)
Study contacts
- Study coordinator: ping h Xie
- Email: hpxie@tjh.tjmu.edu.cn
- Phone: 86+13437187007
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.