New research adds to the growing body of evidence that suggests infants who are born via Caesarian section are more likely to develop allergies later in life.
Published in the journal Gut, the study from Sweden involved 24 infants, nine born via Caesarian section and 15 born through vaginal delivery. The researchers analyzed bacteria (or microbiota) in the babies’ intestines after one week of life, and five more times before the infants reached 2 years of age.
The babies delivered by Caesarian section showed less diversity of microbes in the gut in the first two years of age. They also had significantly lower levels of certain special immune messenger proteins (called chemokines), which help to promote a non-allergic response to allergens.
One group of bacteria in particular, known as Bacteroidetes, was found to be present in lower levels, and with less diversity, in the C-section group. In some cases, colonization by this group of organisms also took place much later for those born via C-section. This is significant because past studies have suggested that the Bacteroidetes are strongly tied to protection against allergies.
The authors conclude that “the early intestinal microbiota exerts important stimuli for immune development, and a reduced microbial exposure as well as Caesarean section has been associated with the development of allergic disease.”
The authors also stress that while a C-section may sometimes be a medical necessity, “it is important that both expectant mothers and doctors are aware that such a delivery may affect the child’s health,” Maria Jenmalm, one of the study authors, said in a press release.