It has been proven beyond any doubt that the bacterial colonisation of a baby’s intestine with the right symbionts is not only important for digestion but also for the development of the child’s immune system. Studies show the many different ways that bacteria can be passed on from mother to child and give us first clues about how the immune system is positively influenced by the microbiome.
How does the gut microbiome develop?
The bacterial colonisation of a child’s intestines while in the womb is still considered a theory among scientists. Even though bacteria can be found in the womb as well as the umbilical cord and placenta, according to recent scientific studies -, scientists are currently unable to prove whether these bacteria colonise the child’s intestines. That is why the mother’s gut flora is so important during and after birth, because that is when it is passed on to the child: During a natural birth, the baby comes into direct contact with the maternal bacterial flora in the birth canal, which then colonise the child’s intestines. In comparison, C-section children show fewer helpful bacteria in their postnatal microbiome and more harmful germs from the hospital’s surroundings are taken in.
Another maternal supplier of vital microbes is breastmilk: It contains several hundreds of different bacterial species, one of the most prominent being Bifidobacteria which support the optimal development of a child’s immune system. Additionally, the surface of the breast also serves as an external source of bacteria for the breastmilk. The following comparison shows the impact that the intake of food has on the development of the infant’s microbiome: Bifidobacteria only make up 50% of the bacterial species in the intestines of infants who were fed with traditional formula. If pre- and probiotics are added to the formula, the amount of Bifidobacteria rises to 69%. Breastfed children benefit the most, as this perfect food for infants contains large amounts of Bifidobacteria and therefore comprises 75% of the bacteria in the infant’s intestines.
A balanced intestinal microbiome during pregnancy, as wells as in the first months of life, is decisive for the optimal development of a child’s immune system.
A dysbalance can be passed on
When the mother has an imbalanced microbiome, whether it is caused by allergies and auto-immune diseases, or is damaged by stress and antibiotics, it can be passed on to the new-born and, as a result, have a negative impact on the development of the baby’s immune system. The dysbalance of the microbiome is associated with an imbalance of certain cells in the immune system, namely T-cells (Th1- and Th2-cells). Studies show that an excess of Th1-associated cytokines is directly related to diseases such as psoriasis and rheumatoid arthritis. An excess of Th2-cells enables the development of allergic diseases such as asthma or eczema. That is why it is so important for all (expecting) mothers to take care of their microbiome to support the bacterial colonisation of their babies as best as possible.
Probiotics shape the development of the immune system
This is where probiotics play an essential role. Their positive effects on the regulation of the microbiome and a dysfunctional immune system are beyond any doubt: During a large placebo-controlled study, expecting mothers, as well as their then newly born babies, received a specially developed multispecies probiotic once a day: Within 3 months after being born, 80% of the allergy-prone children showed a balanced immune system after the intake of probiotics. Even after their second birthday, the effects were still constant in comparison to the placebo-controlled group, even though the children stopped receiving probiotics after their first birthday (Niers 2009). In accordance with recent meta-analyses (Panduru 2015), experts recommend taking specifically combined probiotics during the last 2 months of pregnancy as well as the first whole year of life.
A further study (Kim 2015) analysed the bacterial metabolites (=metabolic products) in the faeces of the then 3-month old children. It revealed that the reduction of allergic diseases is due to the colonisation of various bacteria and the resulting amount of short-chain fatty acids (butyrate, acetate). Healthy children showed significantly higher levels of anti-inflammatory short-chain fatty acids (SCFA, e.g. butyrate) than children with allergies. The results emphasise the importance of a balanced intestinal microbiome during pregnancy, as wells as in the first months of life, to boost the optimal development of the immune system and to give the child a healthy foundation for the rest of its life.
