The prevalence of caesarean section has increased globally in recent decades. While the World Health Organisation suggests that the procedure should be performed in less than 15% of births to prevent morbidity and mortality, the prevalence is higher in most countries. Children born by caesarean section have an increased risk of developing asthma and other immune-mediated diseases compared to children born by vaginal delivery. A link between caesarean section and later disease has been suggested to be mediated through microbial effects.
For the first time, in a new study published in Science Translational Medicine, researchers from Copenhagen Prospective Studies on Asthma in Childhood (COPSAC), University of Copenhagen, Danish technical University and Rutgers University describe how delivery by caesarean section leads to a skewed gut microbiome and associates with asthma development in the first 6 years of life.
Using the well-established Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) mother-child cohort the researchers analyzed the effects of delivery mode on the gut microbiome at multiple timepoints in the first year of life in and to explore whether perturbations of the microbiome can explain the delivery mode-associated risk of developing asthma during childhood.
Increased asthma risk was found in children born by caesarean section only if their gut microbiota at age 1 year still carried a caesarean section signature. No associations with asthma existed from the very early though more pronounced microbial perturbations.
"Even though a child is born by caesarean section and has an immense early microbial perturbation, this may not lead to a higher risk of asthma, if the microbiome matures sufficiently before age 1 year," says Jakob Stokholm, senior researcher and first author on the study.
He continues: "Our study proposes the perspective of restoring a caesarean section perturbed microbiome and thereby perhaps prevent asthma development in a child, who is otherwise in high risk. This study provides a mechanism for the known link between C-section birth and heightened risk of asthma: it is a one-two punch-abnormal early microbiota and then failure to mature."
Søren J. Sørensen, professor at the University of Copenhagen, adds:
"This study has implications for understanding the microbiota's role in asthma development after delivery by caesarean section and could in the future potentially lead to novel prevention strategies and targeted, efficient microbiota manipulation in children who had early perturbations of the microbiome."
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Read the full article 'Delivery mode associates with the risk of childhood asthma partly through long-term microbial changes in the developing gut' in the journal Science Translational Medicine.
Journal
Science Translational Medicine