JUST THE BASICS

Is it possible to prevent allergies? The first step is knowing when and why allergies develop, and this is still an area of research. One thing we have learned is that the immune system seems to have a critical window of time where “early life exposures” can reduce the risk of developing allergies. These exposures seem to help “train” the immune system so it doesn’t overreact when it is exposed to allergens later in life. Studies have shown that early life exposure to farm animals, pets, older siblings, solid foods, and even mom’s bacteria during a vaginal birth may reduce the risk of developing allergies!

TELL ME SOMETHING NERDY

During a vaginal delivery, infants are exposed to maternal vaginal flora and, commonly, maternal fecal flora as well. In fact, passing stool during delivery may actually be an important way for babies to develop healthy gut bacteria. Studies show that babies who are born vaginally will rapidly develop gut colonization with “friendly” bacteria like Bacteroides, while babies born via C-section will have pathogens like Streptococcus and Staphylococcus instead. One study, referenced in the cartoon, attempted to correct this imbalance in C-section babies by mixing a small amount of a maternal stool sample into their first feeding. The babies developed normal gut bacteria as if they were delivered vaginally!

Cartoon published in the August 2024 Annals of Allergy, Asthma & Immunology: https://doi.org/10.1016/j.anai.2023.12.011

Study reference: Korpela K, Helve O, Kolho KL, Saisto T, Skogberg K, Dikareva E, et al. “Maternal Fecal Microbiota Transplantation in Cesarean-Born Infants Rapidly Restores Normal Gut Microbial Development: A Proof-of-Concept Study.” Cell. 2020 Oct; 183 (2): 324-334.