Cesarean birth, early antibiotics alter immunity

Babies born via cesarean delivery and those treated with antibiotics during the first year of life are at least 3 times more likely to develop eosinophilic esophagitis (EoE), according to a new study.

Investigators from the Johns Hopkins Children’s Center and Harvard Medical School report that both situations deprive children of valuable exposure to bacteria, which hinders their ability to build immunity and makes them more prone to allergic inflammation of the esophagus.

To come to that conclusion, the researchers analyzed the medical records and endoscopy results of 99 children aged between 1 and 5 years. About one-quarter of them were diagnosed with EoE. The investigators also gathered information from parents about the children’s symptoms and behavior.

They found that children born via cesarean delivery were 3 times as likely as children born vaginally to develop EoE. Those treated with antibiotics during their first year were 3.5 times as likely as those not treated with antibiotics during the first year to develop EoE. Neither breastfeeding nor the age at which solid foods were introduced altered the risk.

According to Johns Hopkins, EoE is an emerging allergic disease on the rise among both children and adults. The condition is characterized by irritation, inflammation, and constriction of the esophagus and by proliferation of eosinophils. Symptoms include heartburn, difficulty swallowing, and persistent burping. The American Academy of Allergy, Asthma, and Immunology says that infants and toddlers may refuse food or may not grow properly. Because EoE can mimic gastritis, biopsy of the esophagus is the only sure-fire way to diagnose the condition.

Although more research is needed to determine the exact nature of the associations, experts believe that birth via cesarean delivery deprives infants of exposure to bacteria in the birth canal. Similarly, antibiotics given early in an infant’s life kill healthy, as well as unhealthy, gut microflora. Both cause a shift in an infant’s developing immune system, rendering the infant more sensitive to foods and other generally harmless substances. 

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