Genetic sequencing of bacteria in breast milk

Metagenomic Analysis of Bacterial Microbiota in Breast Milk

Observational Centre Hospitalier Sud Francilien · NCT06037421

Researchers will use genomic sequencing to see if bacteria in breast milk given to premature newborns carry virulence genes and whether those genes are turned on.

Quick facts

Study typeObservational
Enrollment120 (estimated)
Ages1 Hour and up
SexAll
SponsorCentre Hospitalier Sud Francilien Academic / other
Locations1 site (Corbeil-Essonnes, France)
Trial IDNCT06037421 on ClinicalTrials.gov

What this trial studies

This observational study collects breast milk, saddle (nipple area), skin, saliva, and blood samples from mothers whose infants are cared for in the CHSF neonatal intensive care unit to profile bacterial communities. Samples will undergo culture to quantify Total Aerobic Flora and identify common enterobacterales and Staphylococcus aureus, while shotgun metagenomic sequencing will determine species, strain relationships, and the presence of virulence genes. The team will also examine whether identified virulence genes are expressed or repressed and compare milk strains with strains responsible for neonatal infections. Results are intended to clarify whether bacterial loads or specific strains in milk represent an infectious risk for premature infants.

Who should consider this trial

Good fit: Women of legal age who gave birth and whose newborns are receiving care in the CHSF Neonatal Medicine and Intensive Care Unit, who intend to provide breast milk and whose parents consent, and who have not received systemic antibiotics in the three months before delivery (aside from intrapartum prophylaxis).

Not a fit: Mothers who received systemic antibiotics within three months before delivery (other than intrapartum prophylaxis) and mother–infant pairs not in the CHSF NICU are unlikely to be eligible or provide data relevant to this study and therefore may not receive benefit.

Why it matters

Potential benefit: If successful, the research could help identify milk-associated infection risks and inform safer milk-handling, screening, and feeding decisions for premature infants.

How similar studies have performed: Previous studies have used metagenomic sequencing to describe breast milk microbiota, but directly linking expressed virulence genes in milk bacteria to neonatal infection risk is relatively novel and not yet well established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Women of legal age who have given birth at the CHSF (or in another establishment) and whose newborn(s) are being cared for in the CHSF's Neonatal Medicine and Intensive Care Unit,
* Women wishing to give their milk to their child,
* Parents who have given their consent for the mother-child couple to take part in the study.

Exclusion Criteria:

* Mother having received antibiotic therapy in the 3 months prior to delivery, except for those who received injectable antibiotic prophylaxis during delivery.

Where this trial is running

Corbeil-Essonnes, France

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bacteria in Breast MilkBacterialnewborn breast milkneonatesinfectious riskvirulence genesagar culture methodsshotgun metagenomics
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.