ClinicalTrials.Veeva

Menu

Effects of Changing Intestinal Transit Time on Gut Microbial Composition and Metabolism (PRIMA-KOST)

University of Copenhagen logo

University of Copenhagen

Status

Completed

Conditions

Metabolic Disease
Diet, Healthy

Treatments

Drug: Diet + laxative
Other: Diet only

Study type

Interventional

Funder types

Other

Identifiers

Details and patient eligibility

About

The aim of this study is to investigate how a short versus a long transit time impacts the gut microbiome's response to a high-fiber and a low-fiber diet, respectively. Such insights could help us understand personal responses to diets and be a first step towards personalized dietary recommendations targeting the gut microbiome.

Full description

The study consists of two parallel arms of whole-meal diets, a low-fiber diet, and a high-fiber diet, respectively. Each arm is designed as a cross-over where participants, in random order, are administered a laxative (Movicol) along with the provided diet to shorten their intestinal transit time or simply consume the provided whole-meal diet (control).

The two intervention periods both involve the following:

  • One week of run-in where participants consume the provided whole-meal diet.
  • One week where participants either consume Movicol with the provided whole-meal diet or simply continue consuming the provided whole-meal diet (control).

Both arms begin with a screening visit and one week where participants consume and record their habitual diets. Subsequently, the first intervention period follows with one visit before and after each of the two weeks (visit 1-3) followed by the second intervention period with one visit before and after each of the two weeks (visit 4-6). The two cross-over periods are split by a washout of at least two weeks.

The study thus runs for approximately 7-8 weeks depending on the length of the washout and consists of seven visits (one screening visit and six regular visits) in total.

Enrollment

22 patients

Sex

All

Ages

18 to 75 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

  • 18.5-30.0 kg/m2 BMI
  • Self-reported ≤3.5 spontaneous bowel movements per week
  • Willing to collect urine and stool samples at home and able to temporarily store them in their own freezer in a provided container.
  • Willing to eat the foods provided.
  • Owns a smartphone (iOS 11.0 and later or Android 5.0 and up) with access to the internet.

Exclusion criteria

  • Pregnant or lactating women.
  • Diagnosis of irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), inflammatory bowel diseases (IBD), Gastrointestinal obstruction, or Ischemic colitis
  • Diagnosed constipation according to the ROME IV criteria
  • Intake of antibiotics ˂ 1month, or any medication that can affect the outcomes of the study
  • Regular use of diarrhea inhibitors or laxatives
  • Dysphagia
  • Any chronic disease that can affect the outcomes of the study or pose a risk when consuming Movicol
  • Intake of medications potentially altering gastric pH (proton pump inhibitors, histamine receptor antagonists, antacids)
  • Intake of medications potentially altering the gastrointestinal motility (prokinetics, antiemetic agents, anti-cholinergic agents, narcotic analgetics, nonsteroidal anti-inflammatory drugs, and peroral glucocorticoids)
  • Concurrent participation in another trial
  • Any condition that makes the project responsible researcher to doubt the feasibility of the volunteer´s participation

Trial design

Primary purpose

Basic Science

Allocation

Randomized

Interventional model

Crossover Assignment

Masking

None (Open label)

22 participants in 2 patient groups

High-fiber diet
Experimental group
Description:
The high-fiber diet will consist of foods rich in dietary fiber such as coarse vegetables, wholegrain bread, and fruits representing a broad range of dietary fibers aiming for ≈40 g of fiber/10 MJ.
Treatment:
Other: Diet only
Drug: Diet + laxative
Low-fiber diet
Experimental group
Description:
The low-fiber diet will consist of foods poor in fiber such as white bread and refined foods aiming for ≈10 g of fiber/10 MJ.
Treatment:
Other: Diet only
Drug: Diet + laxative

Trial contacts and locations

1

Loading...

Central trial contact

Henrik M Roager, PhD

Data sourced from clinicaltrials.gov

Clinical trials

Find clinical trialsTrials by location
© Copyright 2026 Veeva Systems