HealthyYourGutBrainNCT06311097
Dairy Products to Your Gut and Brain
A study testing Fermented dairy and Non-fermented dairy in people with Healthy and Constipation, run by University of Copenhagen at 1 site in Denmark.
Trial summary
The goal of this intervention study is to compare the effects of fermented dairy and non-fermented dairy on bowel habits and cognitive performance in healthy women with defecations every other day or less. Furthermore, the study aims to explore underlying mechanisms linking the gut and the brain. Read more about this study
- Who is it for?
- Ages 45 to 65 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy, Constipation
- What is being tested?
- Fermented dairy and Non-fermented dairy
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 96 participants
- Where
- 1 siteDenmark
- Study dates
- 8 Apr 2024to 3 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 65 years
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Self-reported defecations every second day or less (intervention study only)
- Willing to consume 300g milk/yogurt on a daily basis (intervention study only)
- Owns a smartphone (iOS 11.0 and later or Android 5.0 and up)
- Understand Danish or English
Who cannot join
- Current pregnancy or lactation
- Dairy allergy or intolerance
- Prior diagnosis of psychiatric or neurological illness
- Current diagnosis of depression, anxiety, or stress
- Prior diagnosis of metabolic or gastrointestinal disease (e.g., cardiovascular disease, diabetes, chronic constipation or diarrhea, inflammatory bowel diseases (IBD), celiac disease, small intestinal bacterial overgrowth (SIBO), cancer, etc.)
- Use of antibiotics within the last month
Show all 11Show fewer
- Use of peroral corticosteroids (inhalers excepted)
- Use of medications that alter normal bowel function and metabolism (e.g., laxatives, antidiarrheal agents, narcotics, diuretics, anticonvulsants, etc.)
- Use of neuroactive medications (e.g., antidepressants, anxiolytics, anticonvulsants, antipsychotics, antiparkinsonian, etc.)
- Concurrent participation in another trial
- Any condition that makes the project responsible researcher doubt the feasibility of the volunteer´s participation
Trial locations and contacts
1 site in 1 country.
Denmark1 site
University of Copenhagen, Department of Nutrition, Exercise and Sports
Copenhagen
About this study
The goal of this intervention study is to compare the effects of fermented dairy and non-fermented dairy on bowel habits and cognitive performance in healthy women with defecations every other day or less. Furthermore, the study aims to explore underlying mechanisms linking the gut and the brain.
In addition, a sub-study will be conducted to explore differences in gut and brain measures between women with daily (reference group) and few (intervention group) weekly bowel movements, respectively, and to explore associations between measures of gut- and brain function.
Read the detailed description
Participants in the intervention study (n=60) will consume 300g of fermented dairy (yogurt) or non-fermented dairy (milk) daily for 4 weeks. After a washout period of at least 4 weeks, the participants will consume the alternative dairy product (yogurt or milk) for 4 weeks. The participants will collect samples at home and be tested at the institute before and after each condition (yogurt or milk).
Participants in the sub-study (n=40) will not undergo any dairy interventions and they will only take part in the baseline assessments.
Prior to all visits at the institute, the participants are asked to complete some study activities at home, including:
- consumption of sweet corns to estimate whole gut transit time
- collection of fecal- and urine samples
- measurement of methane and hydrogen in breath
- reporting of gastrointestinal symptoms, including stool frequency and Bristol Stool Scale
During all visits at the institute, the participants will undergo tests and measurements, including:
- measurement of methane and hydrogen in fasting breath
- collection of fasting blood samples
- completion of cognitive tests
- recordings of electrophysiological signals of the gut and the brain
- completion of questionnaires assessing mood, quality of life, and physical activity, among others
- Conditions
- Healthy, Constipation
- Being tested
- Fermented dairy, Non-fermented dairy
- Keywords
- Diet, Fermented dairy, Gut-brain axis, Microbiota
- Medical subject headings
- Constipation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fermented dairyOther
Participants will consume 300g of yogurt daily for 4 weeks as an integral part of their habitual diet, substituting other food items.
Non-fermented dairyOther
Participants will consume 300g of milk daily for 4 weeks as an integral part of their habitual diet, substituting other food items.
| Study group | Role | What they receive |
|---|---|---|
| Fermented dairy | Experimental | The fermented dairy product is Arla A38® naturel 1,5% yogurt. The yogurt contains Lactobacillus acidophilus culture. Receives: Other: Fermented dairy |
| Non-fermented dairy | Placebo comparator | The non-fermented dairy product is Arla® Letmælk 1,5% (semi-skimmed milk). The fermented- and non-fermented dairy products are isocaloric and matched in macronutrient content. Receives: Other: Non-fermented dairy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in change from baseline in defecation frequency between the interventions
Participants will report all bowel movements in a defecation diary in the week leading up to the intervention (baseline) and in the last week of the intervention (week 4)
Measured: Baseline and 4 weeks
Secondary outcomes (7)
Difference in change from baseline in cognitive performance between the interventions
Changes in cognitive performance will be quantified by cognitive index comprising memory, attention, and psychomotor speed. A composite cognitive score will be calculated as the standard score. Z-score will be assessed with the baseline variance between 0 and 1. Memory: number of errors made by the participant. Lower number of errors indicating better outcome. Attention: latency (speed of response), probability of false alarms and sensitivity. Faster speed of response indicating better outcome and lower number of false alarms indicating better outcome. Psychomotor speed: lower values indicating faster reaction time and better outcome
Measured: Baseline and 4 weeks
Difference in change from baseline in phase-amplitude coupling between gastric slow-wave activity and cortical alpha activity between the interventions
Gastric and cortical electrical activity will be measured by electrogastrography (EGG) and electroencephalography (EEG), respectively, to investigate the phase-amplitude coupling between the infra-slow (~ 0.05 Hz) gastric phase and the amplitude of the cortical alpha rhythm (10-11 Hz)
Measured: Baseline and 4 weeks
Difference in change from baseline in whole gut transit time between the interventions
Whole gut transit time will be estimated by sweet-corn passage time
Measured: Baseline and 4 weeks
Difference in change from baseline in stool consistency between the interventions
Changes in stool consistency will be estimated by the Bristol Stool Scale. The scale ranges from type 1 (hard stool) to type 7 (loose stool)
Measured: Baseline and 4 weeks
Difference in change from baseline in stool moisture between the interventions
Fecal water content in percentage of stool weight will be measured
Measured: Baseline and 4 weeks
Difference in change from baseline in fecal abundance of Lactobacillus acidophilus between the interventions
Marker of compliance. Will be assessed by fecal microbiota sequencing
Measured: Baseline and 4 weeks
Difference in change from baseline in self-reported gastrointestinal symptoms between the interventions
Changes in subjective gastrointestinal symptoms will be reported by participants using a visual analog scale.The scale ranges from 0 (no symptoms) to 10 (very bad symptoms)
Measured: Baseline and 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Mar 2024
- Study start8 Apr 2024
- Primary completion3 Dec 2025
- Study completion3 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of CopenhagenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Two 4-week intervention periods separated by a washout period of at least 4 weeks. The crossover intervention will include 60 participants. Another 40 participants will only complete the first (baseline) visit.
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 96 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Copenhagen
- Sponsor type
- University, hospital or other
- Collaborators
- University of Aarhus, APC Microbiome Ireland
- Responsible party
- Principal investigator, Henrik Munch Roager, University of Copenhagen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06311097
- Sponsor's protocol ID
- M402
- Acronym
- YourGutBrain
- Status last verified
- May 2026
- First submitted
- 7 Mar 2024
- Last updated
- 1 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dairy Products to Your Gut and Brain
- ClinicalTrials.gov ID
- NCT06311097
- Acronym / sponsor ID
- YourGutBrain / M402
- Conditions
- Healthy, Constipation
- Keywords
- Diet, Fermented dairy, Gut-brain axis, Microbiota
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 96 participants (actual)
- Lead sponsor
- University of CopenhagenUniversity, hospital or other
- Collaborators
- University of Aarhus, APC Microbiome Ireland
- Study start
- 8 Apr 2024 (actual)
- Primary completion
- 3 Dec 2025 (actual)
- Study completion
- 3 Dec 2025 (actual)
- First posted
- 15 Mar 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this intervention study is to compare the effects of fermented dairy and non-fermented dairy on bowel habits and cognitive performance in healthy women with defecations every other day or less. Furthermore, the study aims to explore underlying mechanisms linking the gut and the brain.
In addition, a sub-study will be conducted to explore differences in gut and brain measures between women with daily (reference group) and few (intervention group) weekly bowel movements, respectively, and to explore associations between measures of gut- and brain function.
Detailed description
Participants in the intervention study (n=60) will consume 300g of fermented dairy (yogurt) or non-fermented dairy (milk) daily for 4 weeks. After a washout period of at least 4 weeks, the participants will consume the alternative dairy product (yogurt or milk) for 4 weeks. The participants will collect samples at home and be tested at the institute before and after each condition (yogurt or milk).
Participants in the sub-study (n=40) will not undergo any dairy interventions and they will only take part in the baseline assessments.
Prior to all visits at the institute, the participants are asked to complete some study activities at home, including:
- consumption of sweet corns to estimate whole gut transit time
- collection of fecal- and urine samples
- measurement of methane and hydrogen in breath
- reporting of gastrointestinal symptoms, including stool frequency and Bristol Stool Scale
During all visits at the institute, the participants will undergo tests and measurements, including:
- measurement of methane and hydrogen in fasting breath
- collection of fasting blood samples
- completion of cognitive tests
- recordings of electrophysiological signals of the gut and the brain
- completion of questionnaires assessing mood, quality of life, and physical activity, among others
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
- Number of arms
- 2
- Model description
- Two 4-week intervention periods separated by a washout period of at least 4 weeks. The crossover intervention will include 60 participants. Another 40 participants will only complete the first (baseline) visit.
| Arm | Type | Receives |
|---|---|---|
| Fermented dairy | Experimental | Other: Fermented dairyThe fermented dairy product is Arla A38® naturel 1,5% yogurt. The yogurt contains Lactobacillus acidophilus culture. |
| Non-fermented dairy | Placebo comparator | Other: Non-fermented dairyThe non-fermented dairy product is Arla® Letmælk 1,5% (semi-skimmed milk). The fermented- and non-fermented dairy products are isocaloric and matched in macronutrient content. |
Who may qualify
- Ages
- 45 to 65 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Self-reported defecations every second day or less (intervention study only)
- Willing to consume 300g milk/yogurt on a daily basis (intervention study only)
- Owns a smartphone (iOS 11.0 and later or Android 5.0 and up)
- Understand Danish or English
Key exclusion criteria (11 listed)
- Current pregnancy or lactation
- Dairy allergy or intolerance
- Prior diagnosis of psychiatric or neurological illness
- Current diagnosis of depression, anxiety, or stress
- Prior diagnosis of metabolic or gastrointestinal disease (e.g., cardiovascular disease, diabetes, chronic constipation or diarrhea, inflammatory bowel diseases (IBD), celiac disease, small intestinal bacterial overgrowth (SIBO), cancer, etc.)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fermented dairyParticipants will consume 300g of yogurt daily for 4 weeks as an integral part of their habitual diet, substituting other food items. | Other | Fermented dairy |
| Non-fermented dairyParticipants will consume 300g of milk daily for 4 weeks as an integral part of their habitual diet, substituting other food items. | Other | Non-fermented dairy |
Primary outcome
Difference in change from baseline in defecation frequency between the interventions
Time frame: Baseline and 4 weeks
Participants will report all bowel movements in a defecation diary in the week leading up to the intervention (baseline) and in the last week of the intervention (week 4)
7 secondary outcomes
Difference in change from baseline in cognitive performance between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in phase-amplitude coupling between gastric slow-wave activity and cortical alpha activity between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in whole gut transit time between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in stool consistency between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in stool moisture between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in fecal abundance of Lactobacillus acidophilus between the interventions
Time frame: Baseline and 4 weeks
Difference in change from baseline in self-reported gastrointestinal symptoms between the interventions
Time frame: Baseline and 4 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jun 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fermented dairy and Non-fermented dairy in people with Healthy and Constipation, run by University of Copenhagen at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in change from baseline in defecation frequency between the interventions (time frame: Baseline and 4 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jun 2026.