NCT06022302

Effects of Changing Intestinal Transit Time on Gut Microbial Composition and Metabolism

Effects of Changing Intestinal Transit Time on Gut Microbial Composition and Metabolism During a Dietary Intervention with Low and High Fiber.

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 22 (actual)
• Sponsor: University of Copenhagen · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

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.

Detailed 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.

Conditions

• Diet, Healthy
• Metabolic Disease

Interventions

Type	Name	Description
DRUG	Diet + laxative	The participants will start by consuming one sacket of Movicol powder (13 g macrogol 3350) on the first day. On day 2, the participants will consume two sackets of Movicol powder (26 g macrogol 3350), one with breakfast in the morning and one before sleep in the evening. The participants will continue consuming two sackets per day (one morning, one evening) until the following study visit, day 8 (seven days in total). If the participants have a very loose stomach (recorded as Bristol stool scale ≥6), they will be instructed to reduce Movicol by one sacket/day. In case the participants have not passed a stool on day 2 or in the morning of day 3, the participants will increase the dose to a maximum of three sackets of Movicol powder (39 g macrogol 3350) per day (morning, noon, and evening) and continue this until the following study visit at day 8. If three sackets cause very loose stomach the participants will decrease the number of sackets consumed.
OTHER	Diet only	This is only a control and participants will not receive Movicol.

Timeline

• Start date: 2023-10-03
• Primary completion: 2024-11-29
• Completion: 2024-11-29
• First posted: 2023-09-01
• Last updated: 2025-03-19

Locations

1 site across 1 country: Denmark