Breastfeeding benefits: Here's how mothers' milk can help infant’s immune system
Breast milk is the best food for an infant from birth. This is a well-established fact for many reasons, one of the most important ones being its benefits for the newborn infant’s immune system.
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FollowThe baby emerges from a completely sterile and infection-free environment into the outer world, which is rampant with various organisms ranging from simple bacteria to drug-resistant ones, viruses, fungi, and parasites. Along with all this, the baby’s immune system is naïve new and still yet to develop memory for various infections. During this time, the baby is susceptible to mild and severe infections.
The early initiation of breastmilk, starting from the first 30 minutes of birth, helps to line the new baby’s gastrointestinal tract with the mother’s milk, which is rich in antibodies called secretory IgA (immunoglobulin A). This IgA helps to bind to the organisms that may enter the gastrointestinal tract and prevent any of these organisms from entering the baby’s body. Other antibodies like IgG, IgM are also present in the breastmilk. These antibodies enter the baby’s bloodstream and help to bind bacteria and viruses, which may enter the infant’s bloodstream. Breast milk also has specific probiotic compounds called human milk oligosaccharides ie the Bifidus factor.
These specific probiotic compounds help to preferentially improve the growth and colonisation of the bacterium called the bifidobacterium, which helps to protect the baby from long-term diseases like allergies, asthma, and obesity. This, hence, lays the foundation for a healthy gut microbiome, unlike that in formula-fed infants.
Breast milk has non-immune and immune cells along with bioactive molecules, namely, cytokines/chemokines, lipids, hormones, and enzymes which play many roles in breastfed newborns by disease protection and shaping the newborn's immune system. Cells like lymphocytes, macrophages and granulocytes are present in the breast milk and these help to develop the baby’s immune system maturity and prevent the development of long term diseases and obesity.
Bioactive components in breast milk are also involved in modulating and titrating an appropriate inflammatory response in breastfed infants. One of these compounds is lactoferrin, which helps absorb iron in breastmilk and makes it bioavailable to the baby. It also helps to prevent iron-feeding bacteria from colonising the infant’s gut.
Maternal antibodies, non-inherited maternal antigens, and maternal leucocytes travel through the stomach and intestine of the offspring after breastfeeding. Also, maternal immune and stem cells invade the newborn blood leading to maternal micro-chimerism and generate immune tolerance. Finally, the breast milk has microbiota, mRNA i, and exosomes which provide immune maturity by T-cell accumulation in the gut of the baby and prevent contracting infections.
Another important aspect of note here is the mother's health and diet. Body weight, age, way of life, and nutrition quality affect the lipid species, microbiota, cytokines, and immune cell type accumulation that makeup breast milk. High-fat, carbohydrate-rich diets disrupt microbiota composition by promoting pathological bacteria, whereas high fibre, with protein and a moderate carbohydrate diet, leads to lactobacillus microbiota in the infant’s gut.
Hence, breastfeeding helps to provide the ideal protection from the organisms in the environment until the baby's immune system is mature. This is why breastfeeding is advised from birth until 2 years of age, as breastmilk provides the ideal immunological programming for the baby.
- Dr. Soundarya M, ConsultantPediatrics, KMC Hospital, Mangalore
