Milk intake and blood microbiome changes in healthy adults

The Effect of Milk Consumption on the Blood Microbiome in Healthy Volunteers

This project will test whether drinking milk increases milk-associated gut bacteria DNA in the blood of healthy adults.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 10 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: Erasmus Medical Center (Academic / other)
• Locations: 1 site (Rotterdam)
• Trial ID: NCT06944002 on ClinicalTrials.gov

What this trial studies

Researchers will enroll healthy adult volunteers who will avoid dairy for ten days and then drink milk daily for seven days while providing blood and fecal samples before the dairy-free period and at 0, 24, and 48 hours and one week after reintroducing milk. Cell-free DNA (cfDNA) from milk-associated intestinal bacteria in blood will be sequenced and compared to fecal cfDNA using a custom bioinformatics pipeline. The aim is to see if the changes seen in fecal samples after milk consumption are mirrored in blood, which would support using blood sampling as a less invasive proxy for gut microbiome changes. The study excludes people with recent antibiotic use, chronic diseases, lactose intolerance, or other conditions that could confound microbiome signals.

Who should consider this trial

Good fit: Healthy adults aged 18–65 with BMI 18.5–25 kg/m2 who are not lactose intolerant, willing to stop other dairy for ten days and drink milk daily, and without recent antibiotics or major chronic illnesses are ideal candidates.

Not a fit: People with chronic diseases, recent antibiotic use, lactose intolerance, pregnancy or breastfeeding, heavy smoking, or BMI outside the specified range are not eligible and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the work could enable less-invasive blood tests to reflect gut microbiome changes, simplifying monitoring and research.

How similar studies have performed: Previous work has detected microbial cfDNA in blood and characterized gut microbiomes, but using blood cfDNA as a validated proxy for the gut microbiome is a novel and not yet established approach.

Eligibility criteria

Inclusion Criteria:

* Age 18-65 years
* 18.5 =\< BMI \< 25 kg/m2
* All genders included
* Not be lactose intolerant
* Willing to consume milk

Exclusion Criteria:

* 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)
* Eating disorder or unconventional eating habits (self-report)
* Participation in another study (self-report)
* Women: pregnancy and breastfeeding (self-report)

Where this trial is running

Rotterdam

• Erasmus MC - Department of Gastroenterology and Hepatology — Rotterdam, Netherlands (Recruiting)

Study contacts

• Study coordinator: Prof. Dr. Maikel P. Peppelenbosch, MD, PhD

Conditions Healthy; The blood microbiome; The gut microbiome; Milk consumption; Healthy volunteers