PEG Laxatives for Intestinal Preparation and Gut Microbiota in Cholecystectomy

NCT07439640 | Recruiting

• 1 other identifier: TJ-IRB202501007
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This observational study aims to investigate the impact of polyethylene glycol (PEG) laxatives used for bowel preparation on the gut microbiota of patients who have undergone cholecystectomy. Emerging evidence suggests that both cholecystectomy and high-dose PEG exposure can independently alter the intestinal microbial ecosystem. However, whether the microbiota of post-cholecystectomy patients is more vulnerable to PEG-induced perturbation and exhibits delayed recovery remains unknown. Approximately 10 adults with prior cholecystectomy scheduled for colonoscopy and 10 age-matched controls without cholecystectomy will be enrolled. All participants will undergo standard colonoscopy preparation with PEG-based laxatives. Stool samples will be collected at five time points: before bowel preparation, at the first non-watery stool after colonoscopy, and at 1, 3, and 6 months post-colonoscopy. Metagenomic shotgun sequencing will be performed to characterise the taxonomic and functional profiles of the gut microbiome. Alpha diversity, beta diversity, differential abundance, and metabolic pathway alterations will be compared within and between groups over time. The findings are expected to reveal whether cholecystectomised individuals are more susceptible to long-term gut dysbiosis after PEG exposure, and to inform future strategies for microbiota restoration in this specific population.

Conditions

Cholecystectomy

Keywords

Gut Microbiota; Colonoscopy

Outcome Measures

Primary Outcomes (1)

• Changes in gut microbial diversity

  Assessment of α-diversity (Shannon index, Simpson index, Chao1 richness estimator) and β-diversity (Bray-Curtis dissimilarity, weighted and unweighted UniFrac distances) based on shotgun metagenomic sequencing of faecal samples. Comparisons will be made within each group across time points and between the gallbladder removal group and the normal group at each time point.

  Baseline (within 3 days before bowel preparation);first non-watery stool after colonoscopy 9up to 48 hours after colonoscopy; 1 month (±7 days) after colonoscopy; 3 months (±14 days) after colonoscopy; 6 months (±14 days) after colonoscopy

Study Arms (2)

Normal group

Individuals with an intact gallbladder, matched for age and sex, who are scheduled for colonoscopy and serve as the control cohort. The same eligibility criteria, exclusion criteria, and observation procedures as the gallbladder removal group apply: participants are aged 18-75 years, free from major organ diseases, and have no recent use of antibiotics, probiotics, or prebiotics. Pregnancy, severe cardiopulmonary insufficiency, mental disorders, and colonoscopy/PEG contraindications are exclusionary. Participants undergo identical PEG-based bowel preparation and provide stool samples at the same five time points. No intervention is administered. Approximately 10 participants are planned for this cohort.

Gallbladder removal group

Individuals who have undergone cholecystectomy at least six months prior to enrolment and are scheduled for a screening or surveillance colonoscopy. Eligible participants are aged 18-75 years, have no history of major organ disease, and have not used antibiotics, probiotics, or prebiotics within six months before enrolment. Exclusion criteria include pregnancy, severe cardiopulmonary insufficiency, mental disorders, and contraindications to colonoscopy or PEG intake. Participants receive standard bowel preparation with PEG-based laxatives according to routine clinical practice. No experimental intervention is administered. Stool samples are self-collected at five time points: within three days before bowel preparation, at the first non-watery stool after colonoscopy, and at one, three, and six months after colonoscopy. A total of approximately 10 participants are planned for this cohort.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients scheduled for colonoscopy at the Department of Gastroenterology, Tongji Hospital, Wuhan, China. Participants are recruited consecutively from the outpatient clinic and voluntarily enrolled after providing written informed consent. Two cohorts are defined based on history of cholecystectomy: individuals with prior cholecystectomy (gallbladder removal group) and individuals with an intact gallbladder (normal group). All participants undergo routine bowel preparation with PEG-based laxatives and provide stool samples longitudinally over a 6-month period. No experimental interventions are administered.

You may qualify if:

• Scheduled to undergo colonoscopy with polyethylene glycol (PEG)-based bowel preparation.
• For the gallbladder removal group: prior cholecystectomy performed at least 6 months before enrolment.
• For the normal group: intact gallbladder (no history of cholecystectomy).
• Willing and able to provide written informed consent.
• Willing to collect and mail stool samples at five specified time points (baseline, first non-watery stool after colonoscopy, 1 month, 3 months, 6 months).

You may not qualify if:

• Contraindications to colonoscopy (e.g., severe cardiopulmonary insufficiency, acute gastrointestinal bleeding, severe coagulopathy).
• Known intolerance or allergy to polyethylene glycol (PEG).
• Use of antibiotics, probiotics, or prebiotics within 6 months prior to enrolment.
• Pregnancy or breastfeeding.
• Mental disorders or any condition that may compromise the ability to comply with study procedures.
• Major organ diseases (e.g., liver cirrhosis, chronic kidney disease stage 4-5, uncontrolled diabetes mellitus).
• Participation in another interventional clinical trial within the last 3 months.

Sponsors & Collaborators

• Tongji Hospital: lead

Study Sites (1)

Department of Gastroenterology Tongji Hospital, Tongji Medical college, Huazhong University of Science and technology

Wuhan, Hubei, 430030, China

RECRUITING

Related Publications (8)

• van der Wulp MY, Derrien M, Stellaard F, Wolters H, Kleerebezem M, Dekker J, Rings EH, Groen AK, Verkade HJ. Laxative treatment with polyethylene glycol decreases microbial primary bile salt dehydroxylation and lipid metabolism in the intestine of rats. Am J Physiol Gastrointest Liver Physiol. 2013 Oct 1;305(7):G474-82. doi: 10.1152/ajpgi.00375.2012. Epub 2013 Jul 18.

  PMID: 23868407 BACKGROUND

• Zou Y, Zeng S, Chen M, Li S, Fu Q, Zhou S, Zhou J. Gut microbiota in children with split-dose bowel preparations revealed by metagenomics. Front Cell Infect Microbiol. 2023 Jul 18;13:1202007. doi: 10.3389/fcimb.2023.1202007. eCollection 2023.

  PMID: 37533931 BACKGROUND

• Batista L, Robles V, Manichanh C, Ruiz L, Guagnozzi D, Pinsach F, Guarner F, Fernandez-Banares F. Colonic bacterial diversity and dysbiosis in active microscopic colitis as compared to chronic diarrhoea and healthy controls: effect of polyethylene glycol after bowel lavage for colonoscopy. BMC Gastroenterol. 2022 Jun 28;22(1):320. doi: 10.1186/s12876-022-02392-w.

  PMID: 35764931 BACKGROUND

• Amaral Raposo M, Sousa Oliveira E, Dos Santos A, Guadagnini D, El Mourabit H, Housset C, Lemoinne S, Abdalla Saad MJ. Impact of cholecystectomy on the gut-liver axis and metabolic disorders. Clin Res Hepatol Gastroenterol. 2024 Aug;48(7):102370. doi: 10.1016/j.clinre.2024.102370. Epub 2024 May 9.

  PMID: 38729564 BACKGROUND

• Tang B, Li S, Li X, He J, Zhou A, Wu L, Xiao X, Wang S, Jiang H, Jian J, Hou Z, Ge Y, Lei Y, Zhou J, Tu D, Lu C, Yang M, Yang S. Cholecystectomy-related gut microbiota dysbiosis exacerbates colorectal tumorigenesis. Nat Commun. 2025 Aug 16;16(1):7638. doi: 10.1038/s41467-025-62956-8.

  PMID: 40819131 BACKGROUND

• Tan L, Jia F, Liu Y. Advances in research on the role of gut microbiota in the pathogenesis and precision management of gallstone disease. Front Med (Lausanne). 2025 Jun 25;12:1535355. doi: 10.3389/fmed.2025.1535355. eCollection 2025.

  PMID: 40636353 BACKGROUND

• McGuinness AJ, O'Hely M, Stupart D, Watters D, Dawson SL, Hair C, Berk M, Mohebbi M, Loughman A, Guest G, Jacka FN. Prior Appendicectomy and Gut Microbiota Re-Establishment in Adults after Bowel Preparation and Colonoscopy. Biomedicines. 2024 Aug 23;12(9):1938. doi: 10.3390/biomedicines12091938.

  PMID: 39335452 BACKGROUND

• Chen J, Sali A, Vitetta L. The gallbladder and vermiform appendix influence the assemblage of intestinal microorganisms. Future Microbiol. 2020 May;15:541-555. doi: 10.2217/fmb-2019-0325. Epub 2020 Jun 1.

  PMID: 32478580 BACKGROUND

Study Officials

• ping h Xie

  Tongji Medical College of Huazhong University of Science and Technology

  STUDY CHAIR

Central Study Contacts

ping h Xie

CONTACT

86+13437187007; hpxie@tjh.tjmu.edu.cn

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: February 13, 2026
• First Posted: February 27, 2026
• Study Start: January 16, 2025
• Primary Completion (Estimated): March 16, 2027
• Study Completion (Estimated): March 16, 2027
• Last Updated: February 27, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)