New study highlights long-term perturbations of the early gut microbiome as a possible mechanism for the observed association between caesarean section and increased risk of developing asthma
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.
“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” says professor Søren Sørensen, University of Copenhagen.
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. Read the article here.
Senior Researcher Jakob Stokholm
Office Phone: +45 38 67 73 60
Professor Søren J. Sørensen
Office phone: +45 51 82 70 07
- Homepage: http://www.bio.ku.dk
Brief facts about the study
The study forms part of an ongoing mother-child cohort study, Copenhagen Prospective Studies of Asthma in Childhood 2010 (COPSAC2010). In the entire cohort of 700 children, 22% were born by CS and 78% by vaginal delivery. The researchers mapped the gut microbiome perturbations in the first year of life. They conclude that delivery by caesarean section was associated with changes in the early life gut microbiota and increased risk of asthma. Among children born by caesarean section, having a highly caesarean section associated microbiota at 1 year of age was associated with later asthma.
COPSAC (Copenhagen Prospective Studies on Asthma in Childhood) is a clinical research unit for asthma studies in children with the aim of developing evidence-based prevention strategies. COPSAC includes a multidisciplinary research cluster with competences in paediatrics, pulmonary disease, allergology, dermatology, microbiology, immunology, genetics, and statistics, and participates in national and international research collaborations. COPSAC is founded and headed by Professor Hans Bisgaard.
Copenhagen Prospective Studies of Asthma in Childhood 2010 (COPSAC2010) is a unique combination of detailed clinical phenotypes, basic research methods, and randomised clinical trials. Recruitment of 736 pregnant women started at the end of 2008 and ended July 2010 with 700 children registered after the last birth in April 2011.
Dept. of Microbiology, University of Copenhagen. The laboratory of Professor Søren J. Sørensen at the Department of Microbiology at University of Copenhagen has been responsible for the sequencing and biological workflow of all COPSAC microbial samples, Professor Sørensen co-supervised the study.