Can a barley and kefir breakfast reshape the gut? trial puts it to the test

NCT ID NCT07864779

Knowledge-focused Sponsor: Western Norway University of Applied Sciences Source: ClinicalTrials.gov ↗

First seen Oct 08, 2026 · Last updated Oct 09, 2026 · Updated 1 time

Summary

Researchers are testing whether eating a daily breakfast of barley porridge and kefir for four weeks changes the mix of bacteria in the gut. The trial enrolls 80 physically active adults aged 18 to 55 who do endurance sports. Half receive the breakfast, half keep their usual diet. Scientists compare stool, blood, and urine samples before and after to see how gut bacteria and related metabolites shift.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance: a daily breakfast of barley porridge and kefir
What this could lead to: If the diet changes gut bacteria, it could point to simple food-based ways to support gut health, recovery, and performance in active people.
What could go wrong: This is a small, four-week study in highly fit adults, so any changes may be modest and may not apply to other groups. Diet studies also struggle to prove cause and effect.

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Study facts

What this study's own registry entry says, in plain language.

Phase

Not a phased trial

Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.

Participants

About 80 people

The number the study aims to enrol. It can still change while the study runs.

Started

Sep 2026

Expected to finish

Jun 2031

An estimate. End dates often move.

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 to 55 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adults aged 18 - 55 years * High aerobic capacity defined by the following minimum estimated VO₂max values: Men: * 20-29 years: ≥ 51 mL/kg/min * 30-39 years: ≥ 47 mL/kg/min * 40-49 years: ≥ 43 mL/kg/min * 50-55 years: ≥ 38 mL/kg/min Women: * 20-29 years: ≥ 44 mL/kg/min * 30-39 years: ≥ 40 mL/kg/min * 40-49 years: ≥ 36 mL/kg/min * 50-55 years: ≥ 32 mL/kg/min Exclusion Criteria: * Pregnancy * Ulcerative colitis * Crohn's disease * Coeliac disease * Milk allergy * Lactose intolerance * Use of antibiotics within the previous 6 months

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As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Gut microbiota diversity and composition Gut microbiota modulation Metabolomics Prebiotic Probiotic

How to take part

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The places running it

1 site. The list below names each one and where it is.
The official record

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Can a barley and kefir breakfast reshape the gut? trial puts it to the test

What the study statuses mean