The intestinal flora of the mother influences the child's immune system

Infant immune system affected by maternal intestinal flora
The intestinal flora has a decisive influence on the immune system and our health. Scientists from the German Cancer Research Center (DKFZ), the Inselspital, the University of Bern and the ETH Zurich have now discovered that the intestinal bacteria of the mother form the baby's immune system during pregnancy.

The composition of intestinal bacteria in the mother has, according to the latest results of the researchers, crucial impact on the immune system of newborns. So far, it has been assumed that adaptation to the child's own intestinal flora takes place only after birth. But obviously the baby's immune system is already in contact with bacteria before birth. "Even during pregnancy, bacteria in the maternal intestine form the baby's immune system," says the DKFZ. The researchers have published their study results in the renowned journal "Science".

Even during pregnancy, the intestinal bacteria of the mother affect the immune system of children. (Image: poplasen / fotolia.com)

Bacterial molecules are transmitted
According to the scientists, babies with an immature immune system are born and so far the assumption was that newborn babies begin to adapt to the many bacteria of their own intestinal flora only after birth. However, the researchers were able to prove in their studies on mice that the intestinal flora of the mother prepares babies during pregnancy for microbial colonization after birth. The effect is due to bacterial molecules that pass through the placenta or are transmitted via antibodies in breast milk.

Beating confrontation with countless bacteria
At birth, the child comes abruptly from the sterile, protected environment of the uterus into a world full of bacteria. Shortly after birth, microorganisms colonize all body surfaces, explains the DKFZ. After only a few days, ten times as many bacteria are found in the intestine as cells in the whole body. Nevertheless, the newborn babies survive the sudden wave of invading bacteria normally without any problems. However, millions of children over the age of five die every year worldwide from intestinal infections. According to the researchers, the biggest problem after birth is that the colon must be colonized with microbes "without infecting the newborn without causing a strong immune response and without restricting the intestinal capacity to absorb nutrients."

Immune system of babies is being prepared
According to current findings, the baby's immune system is being prepared for contact with bacteria before birth. Molecules of the bacteria that live in the maternal intestine first penetrate into the body of the mother and can then be passed on to the child via the placenta or after birth via antibodies contained in the breast milk, reports the DKFZ. These bacterial components are safe and do not cause infection. Instead, they would stimulate cells in the baby's body and prepare their immune system and intestines for the moment after birth, when the newborn baby has to deal with live bacteria in their own gut. Research Director Andrew Macpherson from Bern University Hospital stresses: "We have always known that we should be grateful to our mothers for their love and protective affection. Now we know that we should also thank them for their intestinal flora. "(Fp)