Birth factors influence infant gut microbiome, risk of obesity & allergies

New CHILD research published in the journal Gastroenterology explores how cesarean delivery and other birth events infuence a baby’s gut microbiome at three and 12 months of age, and how this can increase the risk of allergies and obesity later in childhood.

The research used data from 1,667 mothers and infants participating in the CHILD Cohort Study. The researchers analyzed the gut microbes in infant stool samples, and cross-referenced this analysis with body-mass index (BMI) measurements and the results of allergy tests that these same children underwent at one and three years of age.

The study found that infants born by cesarean section were more likely to have a high BMI score at one and three years of age. The researchers also found that at three months these babies had an altered ratio of two bacteria – Enterobacteriaceae and Bacteroidaceae – and that this change represented the dominant path to overweight.

At 12 months of age the same infants had a higher Enterobacteriaceae/Bacteroidaceae (E/B) ratio and colonization with the bacterium Clostridioides difficile (C. difficile), which the researchers identified as the main pathways leading to allergic sensitization.

“Cesarean birth was an initiating event triggering over 100 gut microbial pathways; however, among these, we found that a higher E/B abundance ratio was the dominant compositional change leading to both overweight and allergic sensitization,” explained senior author Dr. Anita Kozyrskyj (University of Alberta). 

Infants born after prolonged labour associated with a first pregnancy were also found to be at a higher risk for these health outcomes, with the E/B abundance ratio again being the most important microbiota mediator to overweight and allergic sensitization, and with Bifidobacterium also playing a role in overweight development.

“The takeaway from our study is that exposures at birth can trigger multiple and common gut microbial pathways leading to child overweight and allergic sensitization,” added Dr. Kozyrskyj.

“We may want to take steps to avoid unnecessary cesarean deliveries and possibly consider microbiota solutions for babies that may help to prevent these two conditions.”

Press Release

Image from the video The CHILD Cohort Study and a baby’s microbiome