An observational study in Breast Milk Collection, Human Milk/Breastfeeding and Human Milk Microbiome, sponsored by University of Aarhus. Active, not recruiting at 1 site in Denmark. Open to female participants, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-29.
Sponsored by University of Aarhus · Observational
This protocol explains the MAINHEALTH cohort. The study examine the influence of maternal health parameters on human breast milk composition and integrates milk phenotype with infant metabolism and infant gut microbial content and metabolism.
The birth of a living human being is the result of an approximately nine-month pregnancy in which the developing foetus has taken exactly the building blocks necessary to grow and develop from its mother. However, growth and development continues in multiple dimensions at an increasing pace after birth. The nutrition in the first 1,000 days from conception to the child's 2nd birthday plays a pivotal role in shaping the future health of the child. Yet, little is known of how breast milk components vary due to maternal factors or of the biological mechanisms behind the beneficial actions of many breast milk nutrients. The investigators propose to overcome these obstacles by combining specialties to give a more complete account of what breast milk is (major and minor milk constituents and microbiota), how it affects the infants directly or indirectly through breast milk-gut microbiome interactions and by which mechanisms. In this study longitudinal samples from 200 mother-infant dyads during the first year of life across three groups of pregestational maternal BMI; normal weight (BMI 18.5-24.99), overweight (BMI 25-30), and obese (BMI >30) are collected. The samples give a comprehensive record of what the infant has ingested (milk samples) and how the infant and infant gut microbiome responds to this (infant urine and feces). Maternal diet in pregnancy and at milk sample deliveries are recorded through a 24h online food recall and diary system. Maternal health attributes will, besides BMI, be analysed through clinical blood biochemistry parameters. Follow-up samples and infant dietary intake as the infant grows allow investigating how early life diet shaped infant growth and gut colonization more long term. The investigators have formed an experienced team of scientists within metabolomics, microbiology and medicine, holding leading positions within their respective fields in Denmark. The novelty in the study is the interdisciplinarity, unique study design and the emphasis to integrate a number of dynamic measurements thereby offering the ability to identify the factors in breast milk affecting infant metabolism and gut colonization. Knowing this enable the optimization of infant formula.
The research questions asked in this project are three-fold.
88 studies on the registry are indexed under Breast Milk Expression; 20 are open to participants now.
This study's enrollment of 168 is above the median of 71 across 36 observational studies indexed under Breast Milk Expression.
Browse Breast Milk Expression studies →University of Aarhus is the lead sponsor of 1,300 studies on the registry; 189 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Residence in Aarhus area is necessary and Aarhus University Hospital has to be the place of giving birth. This is due to samples being collected by midwifes during labor and when study personnel collect samples in study participants' homes.
Inclusion Criteria related to mother:
Exclusion Criteria related to mother:
Inclusion Criteria related to infant:
Exclusion Criteria related to infant:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metabolite profile of human milk
Human milk metabolites by Nuclear Magnetic Resonance (NMR) spectroscopy. Data will be analysed as absolute concentrations of milk metabolites; how milk metabolite profiles are related to mother's blood chemistry, milk microbial profiles, milk oligosaccharides, infant urine metabolome, and infant fecal microbiomes will be explored using multivariate analyses.
Time frame: Birth to 3 months
Metabolite profile of human milk by Liquid Chromatography-Mass Spectrometry (LC-MS) analysis
Human milk metabolites by LC-MS-based metabolomics. Data will be analysed as absolute concentrations of milk metabolites; how milk metabolite profiles are related to milk microbial profiles, milk oligosaccharides, infant urine metabolome, and infant fecal microbiomes will be explored using multivariate analyses.
Time frame: Birth to 3 months
Milk proteome profile
Human milk proteome by LC-MS-based, bottom-up proteomics. Data will be analysed as relative abundances of milk proteins.
Time frame: Birth to 3 months
Milk protein post-translational modification (PTM) profile
Post-translational modifications of human milk proteins is analysed by LC-MS-based and 2D- gel-based proteomics. Data will be analysed as relative abundances of milk protein PTMs.
Time frame: Birth to 3 months
Milk glycome profile
Human milk glycome by LC-MS-based glycomics. Data will be analysed as relative abundances of milk glycans.
Time frame: Birth to 3 months
Microbial structure of human milk
Human milk microbiome by nanopore sequencing. Data will be analysed as relative abundances of bacteria from phylum to genus levels.
Time frame: Birth to 3 months
Microbial structure of infant feces
Infant fecal microbiome by nanopore sequencing. Data will be analysed as relative abundances of bacteria from phylum to genus levels.
Time frame: Birth to 5 years of age
Microbial structure of infant oral cavity
Oral cavity microbiome by nanopore sequencing. Data will be analysed as relative abundances of bacteria from phylum to genus levels.
Time frame: 30 days postpartum
Microbial structure of mother's skin microbiome
Skin microbiome by nanopore sequencing. Data will be analysed as relative abundances of bacteria from phylum to genus levels.
Time frame: 30 days postpartum
Metabolite profile of infant fecal material
Infant fecal metabolome by NMR-based metabolomics. Data will be analysed as absolute concentrations of fecal metabolites
Time frame: Birth to 5 years of age
Infant metabolism investigated by infant urine metabolomics
Infant urine metabolome by NMR-based metabolomics. Data will be analysed as absolute concentrations of urine metabolites
Time frame: Birth to 3 months of age
Microbial structure of maternal vagina and rectum to investigate vertical transmission of bacteria to infant during birth
Vertical transmission of microbiome from mother to infant. Vaginal and rectal microbiome by nanopore sequencing. Data will be analysed as relative abundances of bacteria from phylum to genus levels.
Time frame: During birth
Mother's 24-h dietary recall (myfood24)
Aggregated nutrient intake data (e.g. proteins, vitamins, fibers, omega-3-fatty acids)
Time frame: During pregnancy (Gestational age 30), 30, 60, and 90 days postpartum. In each case two times within a week (one weekday and one weekend day).
Started Jun 2019 (actual). Primary completion is estimated for Feb 2027, 92 months after the start.
Of 25 observational studies under Breast Milk Expression, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 44. This study's planned 92 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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