Breast feeding is recommended worldwide by the World Health Organization (WHO) based on the benefits that are observed from the population studies. The mechanisms were initially explained as the maternal immunoglobulin, intimates of mother and baby and psychological development of the baby.
What is the real reason?
Then it was found that human mothers produce more varied number of complex sugars called oligosaccharides than the other mammals such as cows. These sugars actually can’t be digested and absorbed by the babies, instead are foods for the bacterias in baby’s gut. As a fact of matter these sugars provide a healthier microbiome environment and promotes the favorable germs to grow by providing nutrition to some bacterial subspecies that produce adhesive proteins with immunoprotective and anti-inflammatory functions. Meanwhile, once formula milk is introduced, the gut microbiome gets changed by the formula and becomes different from the breast fed only babies.
Where is the bacteria from?
Recently, more evidence shows that the bacteria on the areolar skin helps the infant bowel to set up gut bacterial communities. Detailed baby’s gut bacteria populational studies show that the similarity of baby’s gut bacteria to the bacteria in breast milk and the areolar skin. Another changer of the baby’s gut microbiome is the mode of delivery, babies from cesarean delivery can never get the microbiome that natural birth babies get.
Back to the initial WHO proposal that breast milk feeding is beneficial to the baby’s immune system development, it is now more obvious the interaction between the gut bacteria and the immune system is transferred to the baby. The baby’s immune system is developmental and weak compared to the adults. The natural transferring from mother to baby helps the baby build up a stronger system, with the results shown in WHO’s population data. A healthy gut microbiome is indispensable not just for the gastrointestinal and immune development, also the neurological development.