HealthyMAMINCT06944002
Milk Consumption and Blood Microbiome in Healthy Volunteers
A study testing Milk product in people with Healthy, run by Erasmus Medical Center at 1 site in Netherlands.
Trial summary
The goal of this study is to learn if cfDNA of milk-associated intestinal bacteria (MAIB) is detectable in the bloodstream. The primary question it aims to answer is: Does milk consumption simultaneously increase the number of MAIB cfDNA counts in blood samples, as it does in fecal samples? Researchers will compare… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Milk product
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 1 siteNetherlands
- Study dates
- 10 Jul 2025to 8 Sep 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 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 18-65 years
- 18.5 =< BMI < 25 kg/m2
- All genders included
- Not be lactose intolerant
- Willing to consume milk
Who cannot join
- Regularly used medications such as antibiotics, steroids, beta blockers, and adrenergic- stimulating agents (self-report)
- Regular use of prebiotic and/or probiotics apart from yogurt and young soft cheese (self-report)
- Antibiotic intake in the previous months (self-report)
- Daily consumption of more than 10 cigarettes (self-report)
- Chronic diseases including type 2 diabetes, hypertension, fatty liver disease, cancer, or autoimmune disease (self-report)
- Internal diseases, including those of the gastrointestinal tract, lung, heart, vasculature, liver, and kidney (self-report)
Show all 9Show fewer
- Eating disorder or unconventional eating habits (self-report)
- Participation in another study (self-report)
- Women: pregnancy and breastfeeding (self-report)
Trial locations and contacts
1 site in 1 country.
Netherlands1 site
Erasmus MC - Department of Gastroenterology and Hepatology
Rotterdam, 3015 GD
About this study
Official title: The Effect of Milk Consumption on the Blood Microbiome in Healthy Volunteers
The goal of this study is to learn if cfDNA of milk-associated intestinal bacteria (MAIB) is detectable in the bloodstream. The primary question it aims to answer is:
- Does milk consumption simultaneously increase the number of MAIB cfDNA counts in blood samples, as it does in fecal samples?
Read more
Researchers will compare cfDNA counts of MAIB to those of fecal samples to assess whether the blood microbiome is a valid measure of the gut microbiome, utilizing a self-developed bioinformatics pipeline.
Participants will:
- Abstain from consuming any dairy products for ten days, followed by drinking milk for 7 consecutive days.
- Provide blood and fecal samples before dairy abstinence, as well as at 0, 24, and 48 hours, and one week after the reintroduction of milk.
Read the detailed description
eDNA (ecological DNA) is a concept that is gaining popularity for making comprehensive descriptions of all organisms present in an ecosystem. Gut microbiomes can be considered a specific variant of eDNA. In theory, a description of the gut microbiome should contain all different kinds of microorganisms in our gastrointestinal tract, including bacteria, viruses, archaea, fungi and other organisms (e.g. worms and phages). In practice, making such descriptions is challenging because of spurious temporal changes and technical challenges (e.g. the commonly used 16S rRNA approach ignores many organisms). Nevertheless, making accurate descriptions is essential as it is generally accepted that the gut microbiome plays critical roles in maintaining host homeostasis and health.
To overcome the challenges in sampling the intestinal microbiome, most investigators currently rely on probing faeces. We have pioneered the field in developing improved technical approaches; for example, we previously performed a double-balloon endoscopic study in healthy volunteers to characterize this microbiome in its entirety. Problems with the faecal microbiome include its poor capture of the adherent flora (which seems the most relevant concerning human physiology), it is highly heterogeneous and can cause results to differ depending on which part of faecal samples was taken, and technological challenges, as many eukaryotes are quite resistant to DNA isolation protocols. Additionally, the faecal microbiome is dominated by diet, which can vary substantially from day to day in humans. For example, faecal material deriving from breakfast can have a significantly different microbiological composition compared to that derived from dinner. Hence, there is a call for alternatives.
The blood microbiome is a newly discovered way of probing the microbiome, integrating the colonization of all kinds of body sites, particularly the intestinal tract. It is speculated that the DNA fragments of various microorganisms enter the circulation through mechanisms that are yet fully understood. The gastrointestinal microbiome is considered a major source of blood microbiome, especially in the case of an impaired gut barrier, which can occur in various chronic diseases.
The description of the entire body of cell-free DNA fragments that derive from non-human origin is called the blood microbiome, even though it does not constitute living organisms, but rather their remnants. The blood microbiome signature has been reported as a predictable biomarker in differentiating patients with cancer from healthy individuals and even for distinguishing between different cancer types. However, the approach remains very controversial due to bioinformatical pitfalls. While we have invested substantial energy in resolving the issues involved, the field requires a formal proof-of-concept to progress. The current study is meant to provide this.
- Conditions
- Healthy
- Being tested
- Milk product
- Keywords
- The blood microbiome, The gut microbiome, Milk consumption, Healthy volunteers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Milk productDietary supplement
The participants will abstain from consumption of any dairy product for ten days and subsequently drink milk for seven consecutive days (700 ml per day), while concomitant consumption of other dairy products is also allowed.
| Study group | Role | What they receive |
|---|---|---|
| Milk consumption | Experimental | Milk consumption for 7 days Receives: Dietary Supplement: Milk product |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in Lactococcus DNA counts
Changes in blood and fecal Lactococcus DNA during milk consumption will be measured with shotgun sequencing technology.
Measured: 10 days before milk consmuption (baseline), 0, 1, 2 and 7 days during milk consumption
Secondary outcomes (1)
Changes in other microbial DNA counts
Changes in other blood and fecal microbial DNA counts during milk consumption will be measured with shotgun sequencing technology.
Measured: 10 days before milk consmuption, 0, 1, 2 and 7 days during milk consumption
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2025
- Study start10 Jul 2025
- Primary completion8 Sep 2025
- Study completion8 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Erasmus Medical CenterThe 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 9 participants (actual)
Sponsor and investigators
- Lead sponsor
- Erasmus Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- NWO (Dutch Organisation for Scientific Research)
- Responsible party
- Principal investigator, Maikel Petrus Peppelenbosch, Erasmus Medical Center
- Investigators
- Prof. Dr. Maikel P Peppelenbosch, MD, PhD, Study chair, Erasmus Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06944002
- Sponsor's protocol ID
- NL88008.078.24
- Other IDs
- KICH2.V4P.22.015
- Acronym
- MAMI
- Status last verified
- Aug 2025
- First submitted
- 11 Apr 2025
- Last updated
- 31 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Anomised IPD used in the results of the publication will be shared in full
Publications
Su J, Hansen BE, Wang Z, Sharmenov A, Xia X, Broekhuizen M, Ma Z, Peppelenbosch MP. Yogurt reintroduction and the circulating microbiome in healthy volunteers: protocol for a prospective, longitudinal, species-controlled crossover clinical trial (MAMI). Contemp Clin Trials Commun. 2025 Nov 24;48:101579. doi: 10.1016/j.conctc.2025.101579. eCollection 2025 Dec.
PubMed 41399631
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Milk Consumption on the Blood Microbiome in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT06944002
- Acronym / sponsor ID
- MAMI / NL88008.078.24
- Conditions
- Healthy
- Keywords
- The blood microbiome, The gut microbiome, Milk consumption, Healthy volunteers
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 9 participants (actual)
- Lead sponsor
- Erasmus Medical CenterUniversity, hospital or other
- Collaborators
- NWO (Dutch Organisation for Scientific Research)
- Study start
- 10 Jul 2025 (actual)
- Primary completion
- 8 Sep 2025 (actual)
- Study completion
- 8 Sep 2025 (actual)
- First posted
- 25 Apr 2025 (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 study is to learn if cfDNA of milk-associated intestinal bacteria (MAIB) is detectable in the bloodstream. The primary question it aims to answer is:
- Does milk consumption simultaneously increase the number of MAIB cfDNA counts in blood samples, as it does in fecal samples?
Researchers will compare cfDNA counts of MAIB to those of fecal samples to assess whether the blood microbiome is a valid measure of the gut microbiome, utilizing a self-developed bioinformatics pipeline.
Participants will:
- Abstain from consuming any dairy products for ten days, followed by drinking milk for 7 consecutive days.
- Provide blood and fecal samples before dairy abstinence, as well as at 0, 24, and 48 hours, and one week after the reintroduction of milk.
Detailed description
eDNA (ecological DNA) is a concept that is gaining popularity for making comprehensive descriptions of all organisms present in an ecosystem. Gut microbiomes can be considered a specific variant of eDNA. In theory, a description of the gut microbiome should contain all different kinds of microorganisms in our gastrointestinal tract, including bacteria, viruses, archaea, fungi and other organisms (e.g. worms and phages). In practice, making such descriptions is challenging because of spurious temporal changes and technical challenges (e.g. the commonly used 16S rRNA approach ignores many organisms). Nevertheless, making accurate descriptions is essential as it is generally accepted that the gut microbiome plays critical roles in maintaining host homeostasis and health.
To overcome the challenges in sampling the intestinal microbiome, most investigators currently rely on probing faeces. We have pioneered the field in developing improved technical approaches; for example, we previously performed a double-balloon endoscopic study in healthy volunteers to characterize this microbiome in its entirety. Problems with the faecal microbiome include its poor capture of the adherent flora (which seems the most relevant concerning human physiology), it is highly heterogeneous and can cause results to differ depending on which part of faecal samples was taken, and technological challenges, as many eukaryotes are quite resistant to DNA isolation protocols. Additionally, the faecal microbiome is dominated by diet, which can vary substantially from day to day in humans. For example, faecal material deriving from breakfast can have a significantly different microbiological composition compared to that derived from dinner. Hence, there is a call for alternatives.
The blood microbiome is a newly discovered way of probing the microbiome, integrating the colonization of all kinds of body sites, particularly the intestinal tract. It is speculated that the DNA fragments of various microorganisms enter the circulation through mechanisms that are yet fully understood. The gastrointestinal microbiome is considered a major source of blood microbiome, especially in the case of an impaired gut barrier, which can occur in various chronic diseases.
The description of the entire body of cell-free DNA fragments that derive from non-human origin is called the blood microbiome, even though it does not constitute living organisms, but rather their remnants. The blood microbiome signature has been reported as a predictable biomarker in differentiating patients with cancer from healthy individuals and even for distinguishing between different cancer types. However, the approach remains very controversial due to bioinformatical pitfalls. While we have invested substantial energy in resolving the issues involved, the field requires a formal proof-of-concept to progress. The current study is meant to provide this.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Milk consumption | Experimental | Dietary Supplement: Milk productMilk consumption for 7 days |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age 18-65 years
- 18.5 =< BMI < 25 kg/m2
- All genders included
- Not be lactose intolerant
- Willing to consume milk
Key exclusion criteria (9 listed)
- Regularly used medications such as antibiotics, steroids, beta blockers, and adrenergic- stimulating agents (self-report)
- Regular use of prebiotic and/or probiotics apart from yogurt and young soft cheese (self-report)
- Antibiotic intake in the previous months (self-report)
- Daily consumption of more than 10 cigarettes (self-report)
- Chronic diseases including type 2 diabetes, hypertension, fatty liver disease, cancer, or autoimmune disease (self-report)
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 |
|---|---|---|
| Milk productThe participants will abstain from consumption of any dairy product for ten days and subsequently drink milk for seven consecutive days (700 ml per day), while concomitant consumption of other dairy products is also allowed. | Dietary supplement | Milk consumption |
Primary outcome
Changes in Lactococcus DNA counts
Time frame: 10 days before milk consmuption (baseline), 0, 1, 2 and 7 days during milk consumption
Changes in blood and fecal Lactococcus DNA during milk consumption will be measured with shotgun sequencing technology.
1 secondary outcome
Changes in other microbial DNA counts
Time frame: 10 days before milk consmuption, 0, 1, 2 and 7 days during milk consumption
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 31 Aug 2026.
- Derived from this study: PubMed 41399631Su J, Hansen BE, Wang Z, Sharmenov A, Xia X, Broekhuizen M, Ma Z, Peppelenbosch MP. Yogurt reintroduction and the circulating microbiome in healthy volunteers: protocol for a prospective, longitudinal, species-controlled crossover clinical trial (MAMI). Contemp Clin Trials Commun. 2025 Nov 24;48:101579. doi: 10.1016/j.conctc.2025.101579. eCollection 2025 Dec.
- Individual participant dataSharing planned: Yes. Anomised IPD used in the results of the publication will be shared in full
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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.
Prof. Dr. Maikel P Peppelenbosch, MD, PhD study chair
Erasmus Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Milk product in people with Healthy, run by Erasmus Medical Center at 1 site in Netherlands.
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 5 inclusion and 9 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 31 Aug 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 Netherlands. 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. 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?
Changes in Lactococcus DNA counts (time frame: 10 days before milk consmuption (baseline), 0, 1, 2 and 7 days during milk consumption). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06944002, which also lists 1 linked publication.
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 31 Aug 2026.