Can fasting rewrite the microbes in your blood?

NCT ID NCT06678516

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Recruitment status, easiest to join first

Recruiting now This study
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
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Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

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Status unknown
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First seen Sep 11, 2026 · Last updated Sep 11, 2026

Summary

Researchers at Erasmus Medical Center are studying whether one month of daily intermittent fasting changes the mix of bacteria, archaea, and viruses in the blood of healthy volunteers. Participants follow their usual eating habits for one month, then fast from 7:30 to 18:30 each day for another month, drinking only water or zero-calorie beverages during fasting hours. The team uses genetic sequencing to compare blood microbe samples before and after fasting, and also looks at how blood microbes relate to gut microbes. The goal is to understand whether fasting, a common lifestyle change, alters the blood microbiome in ways that could matter for future disease detection.

What this could mean

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

Active substance
intermittent fasting, a schedule where people eat only during certain hours of the day
What this could lead to
If fasting shifts the microbes in blood, doctors might one day use blood microbe patterns to spot liver disease early or to guide lifestyle advice.
What could go wrong
This is a small, short study in healthy people, so any changes may be minor, temporary, or not apply to sick patients. Fasting can cause hunger, headaches, or low energy, and the blood microbiome is a new field with no proven clinical use yet.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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 48 people

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

Started

Dec 2025

Expected to finish

Nov 2027

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 65 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: * Age 18-65 years * 18.5 =\< BMI \< 25 kg/m2 * All genders are included. * Have not fasted (go for a day without any food) for any amount of days in the month before the start of the study * Being willing to provide App-derived movement data over the course of the study * Participants are willing to and capable of providing written informed consent. Exclusion Criteria: * Regular use medications such as antibiotics, steroids, beta blockers, and adrenergic-stimulating agents (self-report) * Regular use prebiotic and/or probiotics (self-report) * Intake of antibiotic at least in previous 1 months (self-report) * Daily consumption of \>10 cigarettes, or \>6 cups of coffee (the latter because of the effects on circadian rhythm). (self-report) * Chronic diseases including type 2 diabetes, hypertension, fatty liver disease, cancer, or autoimmune disease (self-report and clinical chemistry) * Internal diseases, including those of the gastrointestinal tract, lung, heart, vasculature, liver, and kidney (self-report and clinical chemistry) * Eating disorder or unconventional eating habits (self-report) * Have a clinically significant abnormality as measured by a blood test * Participation in another study (self-report) * Habit of performing regular fasting (self-report) * Women: pregnancy and breastfeeding (self-report)

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Conditions

The condition(s) this trial relates to.

Intermittent Fasting

As listed by the trial registrant

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

How to take part

Only the study team decides who joins. These are the ways to reach them.

  1. The places running it

    2 sites in 2 countries. The list below names each one and where it is.

  2. The official record

    ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.

    Open the record ↗

  3. A doctor treating you

    A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.

Contacts and locations

Locations

  • Erasmus Medical Center - Department of Gastroenterology and Hepatology

    RECRUITING

    Rotterdam, 3015 GD, Netherlands

  • Northwest Minzu University

    RECRUITING

    Lanzhou, Gansu, 730046, China

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