Babies born by caesarean section have different gut bacteria, or microbiome, compositions to babies born vaginally, new research shows.

The Microbiome is Essential to Childhood Health

The gut microbiome is the ecosystem of bacteria resident in our gut. Recent research has only scratched the surface on uncovering the instrumental role the microbiome plays in our health. Exposure to the right bacteria in early childhood is though to be essential for developing a healthy immune system whilst a lack of exposure has been linked to the development of asthma, diabetes and allergies. However, there has been a lack of research investigating the factors that influence microbiome composition in early childhood, including delivery method.

Delivery Method and the Microbiome

Faecal samples were taken from 600 healthy babies, who had been delivered either vaginally or by caesarean section. Samples were taken when the babies were four, seven and 21 days old, with some babies being followed up a year later. It was found that babies born vaginally had more gut bacteria shared with their mother, whilst babies born by caesarean section had more gut bacteria associated with the hospital environment. Some of the hospital associated bacteria was found to have antibiotic resistance. However, the gut bacteria from the vaginally delivered babies was not found to originate from the mother’s vagina, but instead from the mother’s gut. This raises concerns about the controversial healthcare practice of swabbing caesarean born babies with their mother’s vaginal bacteria.

Developing a Healthy Immune System

Interestingly, the differences in microbiome between babies born by caesarean and vaginally delivered babies evened out after weaning. However, as the first few weeks of a baby’s life are instrumental to the development of the immune system more research is needed to determine if the early discrepancies in microbiome composition can lead to health impact later in life.

The researchers stress that this new information should not deter woman from having caesarean sections, as in many cases it is a life-saving procedure and the health impacts from the microbiome are not well understood.