From 1 to 7 August, we mark World Breastfeeding Week, an annual campaign that highlights the benefits of breastfeeding and the importance of protecting and supporting it. At the same time, there is still much we do not know about breast milk. What does it contain? And what role do its components play in the health and development of both mother and child? These are some of the questions being explored in Lifelines NEXT.
Lifelines NEXT is a birth cohort that follows pregnancy and the health of mothers and their children while collecting a wide range of health and biological data. Nearly 1,500 mothers are taking part. The study is a collaboration between the Departments of Obstetrics and Gynaecology, Paediatrics, Health Sciences and Genetics at the University Medical Center Groningen.
Johanne Spreckels works in the Department of Neonatology and carried out her research within Lifelines NEXT. What makes breast milk such a fascinating topic to study?
Johanne explains: "Previous research has shown differences in both short- and long-term health outcomes between babies who are formula-fed and those who receive breast milk. Babies who are breastfed appear to experience fewer infections during infancy, which is associated with a lower risk of infection-related mortality. In the longer term, breastfeeding has been linked to a reduced risk of overweight, obesity and diabetes, and even to a greater likelihood of higher cognitive performance."
Within Lifelines NEXT, Johanne investigated how mothers' genes, lifestyle and environment influence the composition of breast milk. She focused on prebiotic sugars, which help support the growth of beneficial gut bacteria, and on the bacteria naturally present in breast milk. The study showed that breast milk does not have a fixed "recipe". Instead, it is a dynamic fluid that continuously adapts to meet a baby's changing needs.
Together with her colleagues, Johanne analysed 1,542 breast milk samples from 524 mothers. The samples were collected between two weeks and six months after birth. "The mothers expressed their milk at home and stored it in their freezer until a research nurse collected it," Johanne says. "We then analysed the samples in the laboratory." The findings revealed that breast milk changes as babies grow older. "We found that breast milk adapts as a baby develops. For example, the concentration of prebiotic sugars gradually decreased over time, while the diversity of bacteria increased. We also found that some of these milk sugars and bacteria contribute to the development of a baby's gut microbiome."
A better understanding of breast milk may also help improve infant formula. But how?
Johanne explains: "For example, by adding specific prebiotic sugars or probiotic bacteria to infant formula, we may be able to make the gut microbiota of formula-fed babies more similar to that of breastfed babies. Although we are unlikely ever to replicate all of the immunological components of breast milk, this knowledge allows us to continue improving infant formula."
Lifelines NEXT is one of more than 175 cohorts and biobanks at the University Medical Center Groningen. Cohorts and biobanks are essential for health research, offering extensive data for innovative medical studies. The Cohort and Biobank Coordination Hub (CBCH) serves as a central facilitator and linking pin for all UMCG cohort and biobank activities. We bring together a community of researchers and clinicians, and provide an excellent infrastructure to drive new discoveries.
