The First 1000 Days: Why the Baby Microbiome is Particularly Important

In recent years, the gut flora, also known as the intestinal microbiome, has emerged as the "last discovered organ of the human body", becoming increasingly present in our collective consciousness. We now know that our gut bacteria play an important role in our health: They assist us in digestion, train our immune system, and even influence our mental health through the gut-brain axis.

Especially in babies, a healthy microbiome plays a particularly important role. For example, during the first 1,000 days of life, the gut flora is involved in shaping the immune system, which can have later health implications.

In a normal, healthy pregnancy, the child in the womb is completely free of bacteria. As soon as the birth process begins, the baby comes into contact with bacteria from the outside world for the first time.

Babies born naturally acquire vaginal and intestinal bacteria of the mother during the journey through the birth canal. Children born via cesarean section first acquire skin bacteria from the mother when they are placed on the mother's chest after birth. Epidemiological studies have shown that children born via cesarean section have, among other things, a higher risk for allergies and asthma, type 1 diabetes, and obesity.

Moreover, external factors such as diet (breastfeeding or bottle) and the administration of antibiotics can influence the child's gut flora.

Current studies also indicate that the microbiome in the first 1,000 days of life is particularly sensitive to changes and influences.

The gut flora of adults remains quite constant, but in babies and toddlers, it changes continuously. Initially, it is completely adapted to milk nutrition and gradually adapts, with the addition of complementary foods, until it finally resembles that of an adult's gut flora.


Therefore, a healthy microbiome in the first 1,000 days of life is not only important for the healthy development of the baby. This phase also offers the best opportunity to positively and sustainably influence the gut flora.
 

Sources:

1. Roswall, J., et al., Developmental trajectory of the healthy human gut microbiota during the first 5 years of life. Cell host & microbe, 2021
2. Olszak, T., et al., Microbial exposure during early life has persistent effects on natural killer T cell function. Science, 2012
3. Cryan, J.F., et al., The microbiota-gut-brain axis. Physiological reviews, 2019
4. Stewart, C.J., et al., Temporal development of the gut microbiome in early childhood from the TEDDY study. Nature, 2018
5. de Goffau, M.C., et al., Human placenta has no microbiome but can contain potential pathogens. Nature, 2019
6. Dominguez-Bello, M.G., et al., Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns. Proceedings of the National Academy of Sciences, 2010
7. Magne, F., et al., The elevated rate of cesarean section and its contribution to non-communicable chronic diseases in Latin America: the growing involvement of the microbiota. Frontiers in pediatrics, 2017
8. Bokulich, N.A., et al., Antibiotics, birth mode, and diet shape microbiome maturation during early life. Science translational medicine, 2016