Birth by Caesarian section weakens the gut microbiota, leading to increased risk of developing allergies, according to a study by universities in Sweden and Scotland.
The researchers from, among others, the KTH Royal Institute of Technology and Science in Stockholm and the University of Glasgow, followed gut microbiota development in 24 children up to the age of two, nine delivered through Caesarean and 15 delivered naturally, through vaginal birth.
Those that were delivered by Caesarean section had a less diverse gut microbiota during their first two years of life than those born vaginally. The low diversity was particularly clear among bacteroidetes, which are chiefly associated with protection against allergies. Thus, these children may run greater risk of developing allergies, but diabetes and irritable bowel syndrome are also more common among them.
Everything indicates that right up until the moment of birth the child's gut is completely sterile. With natural birth the child is exposed to bacteria in the mother's birth canal, a good start to the formation of the child's own gut microbiota.
Besides a greater diversity in their intestinal flora, children delivered vaginally in the Linköping study also had higher blood plasma levels of substances linked to Th1 cells, a kind of "chief cells" in the immune system, which can inhibit allergic immune responses.
"Sometimes Caesarean sections are necessary. But it is important that both expectant mothers and doctors are aware that such a delivery may affect the child's health," said Maria Jenmalm from Linköping University, one of the authors of the article.
