C-section children receive important microbes from their mothers

A caesarean section does not necessarily mean that the baby is missing important microorganisms from the mother. This is what a research team reports in the journal “Cell Host

On our skin, our mucous membranes, in our intestines and other organs there is a unique community of bacteria, viruses, fungi and other microorganisms that is essential for our health. The course for this microbiome is already set during birth - in fact, the first colonization with microbes takes place during the course of childbirth.

Their type influences the composition of the child's microbiome: Caesarean babies hardly come into contact with the mother's vaginal and faecal microorganisms during the birth process. A research team led by Wouter de Steenhuijsen Piters from the University Hospital Utrecht has now investigated how this lack of contact, as well as other factors, affects the development of the microbiome in babies.

The doctors used data from 120 births in the Netherlands: microbiome samples from the skin, nose, saliva and saliva were taken from the babies two hours after birth and at the age of one day, one week, two weeks and one month taken from the intestine. At the same time, the scientists collected samples of the maternal microbes from skin, breast milk, nose, throat, fecal matter and vaginal samples to determine which sources fed the babies' microbiomes. They then analyzed the results related to various factors thought to impact microbiome transfer, including delivery mode, antibiotic use and breastfeeding.

The team found that multiple maternal microbiome sources are important for transmission of the microorganisms. "If some of these pathways are blocked for one reason or another - like during a cesarean section - then these microbes can still reach the infant through other pathways," explained de Steenhuijsen Piters.

Regardless of the birth route, 58.5 percent of a baby's microbiome came from the mother. Babies born by cesarean section received fewer microbes from their mother's vaginal and fecal microbiome, but—apparently to compensate—acquired more microbes from breast milk. This makes breastfeeding all the more important for her, emphasized lead author Debby Bogaert from the University of Edinburgh.

She summarized: "The transmission and development of the microbiome is so essential that evolution has arranged for these microbes to be transmitted from mother to child in one way or another." De Steenhuijsen Piters added that that intelligent system ensure that a child can start life with the right "starting kit".

Now the research team wants to learn more about the non-maternal influences on the development of the child's microbiome. "We were able to find that the maternal microbiome explains almost 60 percent of the total infant microbiome, but there is still 40 percent that we don't know anything about," said de Steenhuijsen Piters. "It would be interesting to determine this unknown proportion to find out where all the microbes come from, whether for example the fathers, the siblings or the environment contribute to it."

Just recently, a study published in the journal "Nature" showed that at least children from the age of four share a similar number of intestinal microbial strains with their father as with their mother.

Ultimately, the authors of the current study want to understand how the development of the microbiome in infants affects their long-term health. "Next we want to investigate whether this early life process, which is influenced by the mother, influences not only the short-term risk of infection in the first year of life, but also longer-term health in terms of allergies and asthma," explained Bogaert. "In the future, we may be able to use this knowledge to prevent, diagnose, or treat health problems."

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