Digestion and gut function after bariatric surgery

Gastro-Intestinal Digestion and Physiology After Bariatric Surgery

Observational Universitaire Ziekenhuizen KU Leuven · NCT07286968

This project will test how digestion — including enzymes, bile acids, pH, and transit time — works in adults with obesity and in people at least one year after Roux‑en‑Y or sleeve gastrectomy by collecting intestinal samples and using a swallowable sensor capsule.

Quick facts

Study typeObservational
Enrollment51 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorUniversitaire Ziekenhuizen KU Leuven Academic / other
Drugs / interventionschemotherapy
Locations1 site (Leuven)
Trial IDNCT07286968 on ClinicalTrials.gov

What this trial studies

Adults aged 18–65 with obesity (BMI >30) or at least one year after Roux‑en‑Y or sleeve gastrectomy will be enrolled. In the first visit, researchers will collect aspirates from multiple regions of the gastrointestinal tract via a naso‑intestinal catheter to measure gastric and pancreatic enzyme activity and bile acid concentrations. In a second visit participants will swallow an ingestible telemetric capsule that continuously records pH and other physiological parameters along the entire gut to determine transit times. The observational protocol aims to compare regional digestion and physiology after bariatric surgery with findings in people living with obesity.

Who should consider this trial

Good fit: Ideal candidates are adults 18–65 with BMI >30 or individuals at least one year after a single Roux‑en‑Y or sleeve gastrectomy who can tolerate naso‑intestinal sampling and swallowing a telemetric capsule.

Not a fit: Patients with more than one bariatric surgery, recent gastrointestinal surgery, implanted electromedical devices, swallowing disorders, or an excessive waist circumference are unlikely to qualify or benefit from this protocol.

Why it matters

Potential benefit: If successful, the results could enable more tailored nutritional guidance, enzyme or bile‑related therapies, and better symptom management for people after bariatric surgery.

How similar studies have performed: Related techniques like intestinal aspirates and ingestible telemetric capsules have been used successfully to measure pH and transit time, but comprehensive enzyme and bile acid profiling after bariatric surgery remains relatively undercharacterized.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Participants eligible for inclusion in this Investigation have to meet all of the following criteria:

1. Voluntary written informed consent of the participant has been obtained prior to any screening procedures
2. Age: 18-65 years

   Specific inclusion criteria for the different patient populations:

   Patients with obesity:
3. Body Mass Index: \> 30 kg/m2

   Patients after bariatric surgery:
4. Surgery: at least one year after Roux-en-Y gastric bypass or sleeve gastrectomy

Exclusion Criteria:

Participants eligible for this Investigation must not meet any of the following criteria:

1. Patient has history of more than one bariatric surgery
2. Patient has a waist circumference \> 125.6 cm
3. Patient had gastrointestinal surgery in the past three months
4. Patient has a pacemaker, defibrillator, infusion pump, or other portable or implanted electromedical device
5. Patient had frequent exposure to X-rays in the past year
6. Patient has swallowing disorders, among others: dysphagia for food or pills, any oropharyngeal or oesophageal stricture, anxiety or functional abnormality
7. Patient has Crohn's disease or Diverticulitis
8. Patient has gastrointestinal strictures, fistulas or physiological/mechanical obstructions
9. Patient has gastric bezoar
10. Patient has a history of complex bowel resection or known abdominal adhesions
11. Patient has short bowel syndrome or ostomy
12. Patient has currently ongoing infections
13. Patient is planned to undergo usage of rectal foam/enema or treatment with adjuvant chemotherapy or radiotherapy
14. Patient is currently on parenteral diet
15. Patient is planned to undergo MRI procedure during usage of the wireless capsule
16. Patient is working in a professional healthcare facility (e.g. hospital, dental office, emergency room), military area (e.g. submarine, near radar installation), or heavy industrial area (e.g. power plants, automotive, mining, refineries) during the duration of the clinical investigation
17. Patient is pregnant, breastfeeding, actively trying to get pregnant or had recent childbirth in last 6 months
18. Patient cannot discontinue medication that affects gastrointestinal transit time and/or pH for at least 3 days before and during the study (and 4 weeks for weekly/long-acting GLP-1 analogues such as Saxenda, Ozempic, Wegovy, Mounjaro). This includes opioids (e.g., morphine, codeine), proton pump inhibitors (e.g., omeprazole, esomeprazole, pantoprazole), H2-receptor antagonists (e.g., cimetidine, famotidine), antacids, sucralfate, prokinetics (e.g., domperidone, metoclopramide), antidiarrheal agents (e.g., loperamide), antibiotics, probiotics and prebiotics.
19. Any disorder, which in the investigator's opinion might jeopardise participant's safety or compliance with the CIP.

Where this trial is running

Leuven

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bariatric SurgeryRoux-en Y Gastric BypassSleeve GastrectomyObesity & OverweightGastro-intestinal aspirationingestible telemetric capsule
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.