Gastrointestinal Transit Time Baseline in Healthy Adults

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This cross-sectional study aims to establish population reference values for gastrointestinal transit time (GITT) using a blue-dye muffin method. After a two-day standardized lifestyle period, participants ingest a blue muffin at a research center, provide blood samples for metabolic profiling, and supply stool samples for moisture analysis, while completing detailed lifestyle and bowel habit questionnaires. GITT is calculated from the time between muffin ingestion and first blue stool, plus the interval to complete blue color disappearance. The study will also explore associations between GITT and biochemical parameters, fecal moisture, and lifestyle factors. The approach builds on established methods with refined pre-test controls to improve reliability in a large, diverse adult population.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. 18-65 years old
2. 18.5 kg/m² ≤ BMI ≤ 25 kg/m² or BMI ≥ 30 kg/m² (people with normal weight or obesity)
3. Provision of informed consent to participate.

Exclusion Criteria:

1. Gastrointestinal conditions which may affect nutrient absorption or gastric emptying, including coeliac disease, Crohn's disease, previous resection of the small intestine other than bariatric surgery, gastroparesis;
2. Using medications which effect gastric motility (e.g., domperidone, erythromycin, metoclopramide, prucalopride, opiates, loperamide, …)
3. The ingredients of blue muffins include gluten, nuts, baking powder, sugar, vanilla extract and sunflower oil. Participants with allergies to these ingredients;
4. Current diagnosis of cancer;
5. Advanced organ failure, including chronic kidney disease Stage 5, liver cirrhosis Child-Pugh B or C, intestinal failure, heart failure stage D, or chronic obstructive pulmonary disease stage 4;
6. Immobility;
7. Neuromuscular degenerative conditions associated with muscular atrophy, such as myasthenia gravis, muscular dystrophies, fibromyalgia, or multiple Sclerosis;

Where it's running

• Department of Chronic Diseases and Metabolism
  Leuven, Flemish Brabant, Belgium Recruiting

Study contacts

• Study coordinator: Christophe Matthys
• Email: christophe.matthys@uzleuven.be
• Phone: +32 016342655

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.