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NCT07691736Recruiting

Combining Fasting and Fibre Interventions to Optimise Their Gut Microbiome-mediated Health Benefits

Source: ClinicalTrials.gov · Last updated 30 Sept 2026

Brief summary (registry, in English)

This study builds on the knowledge that fasting provides metabolic health benefits and that prebiotic interventions can enhance the gut microbiome's metabolic output to likewise improve host health. Whether long-term fasting and dietary fibre interventions could be combined to achieve synergistic improvements in host metabolic health is however unknown. The goal is to provide a proof of concept in a human trial that supplementing 10±4 days fasting with dietary fibre synergistically improves metabolic outcomes via gut microbiome-mediated effects. To assess this, we aim to analyse gut microbiome changes, functional outputs, and key metabolic markers such as butyrate production, glycaemic control and ketosis. The randomised controlled trial includes 75 participants and has two arms: one involving fasting with fibre supplementation (n = 50) and one involving fasting without fibre supplementation (n = 25). All participants will undergo a fasting period of 10±4 days according to the Buchinger Wilhelmi protocol, followed by a stepwise reintroduction of food of up to 4 days. As dietary fibre we will use maize-derived resistant starch type IV, selected based on its ability to stimulate beneficial gut microbes like Oscillibacter and corn starch as placebo. Two main visits will be conducted: before and at the end of the fasting period. During these visits, blood and stool samples will be collected, and questionnaires will be completed. Additionally, daily measurements of anthropometric parameters and well-being will be recorded. Stool samples will also be collected one month afterwards as a follow-up. Participants' metabolic health will be evaluated through various clinical parameters (e.g., body measurements, blood pressure, glycaemic control, ketones, well-being). Additionally, multi-omics data, including metagenomics and metabolomics, will provide insight into the composition of the microbiome, as well as its outputs and functions. Furthermore, the effects of fasting on extracellular vesicles in blood will be explored.

Status (registry)
Recruiting
Study type
Interventional
Enrollment
75 (estimated)
First submitted
24 Jun 2026
Start date
31 Aug 2026
Primary completion date
28 Feb 2027
Lead sponsor
Buchinger Wilhelmi Development & Holding GmbH
Diseases
Obesity
NCT number
NCT07691736

What you commit to

  • Study type: Interventional
  • Planned participants: 75
  • From 31 Aug 2026 to the primary completion date, 28 Feb 2027
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Prior treatment

  • intake of antibiotics up to 2 months prior the study
  • regular intake of pre-, post- and probiotics up to 2 months prior the study

Other illness

  • diagnosed Crohn's disease, Ulcerative colitis, IBD, coeliac disease
  • diagnosed diabetes mellitus type I
  • medicated diabetes mellitus type II
  • active malignant disease
  • diagnosed with cachexia, anorexia nervosa, advanced kidney, liver or cerebrovascular insufficiency

Other

  • medicated high blood pressure
  • diagnosed kidney stone
  • known substance addiction
  • pregnancy or breastfeeding
  • inability to sign the informed consent
  • participation in another study

Who the study is looking for

  • Men and women
  • Age: 18-65 years old
  • Fasting for 10±4 days at the Buchinger Wilhelmi clinic in Überlingen
  • BMI ≥ 25 kg/m²
  • Signed informed consent

Age in the registry: 18 years to 65 years · Sex: All · Accepts healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Save your city in your profile to sort them by distance.

SiteCityCountrySite status
Buchinger Wilhelmi Development & Holding
Coordinator of this site? Confirm its status
ÜberlingenGermanyRecruiting

This page is information, not medical advice. Discuss any trial with your doctor.