Scientists have uncovered that antibiotics administered to newborns can alter gut bacteria, potentially leading to increased susceptibility to allergies. The research, conducted at the University of British Columbia (Canada), reveals that these changes in gut microbiota can have long-term effects on the immune system throughout life.
Certain gut bacteria produce butyrate, a compound critical for suppressing immune processes that drive allergy development. Antibiotics, however, reduce the population of these bacteria, disrupting butyrate production.
“Our research demonstrates how antibiotics shape a newborn’s immune system by altering gut bacteria, making them more prone to allergies,” said senior author Dr. Kelly McNagny. “This understanding fundamentally shifts how we think about chronic diseases and their origins.”
Studies using mice have shown that the absence of butyrate leads to a doubling of ILC2 cells, a type of immune cell linked to allergies. These cells produce molecules that trigger white blood cells to create an excess of certain antibodies, priming the immune system for hypersensitivity reactions. This chain reaction is dramatically amplified in the absence of butyrate.
The researchers found that butyrate supplementation during a critical early-life window can prevent these immune changes. However, if this window is missed, the allergic cascade becomes irreversible.
The researchers have identified potential methods to prevent allergy development, even after the early-life window for butyrate supplementation has passed. Targeting ILC2 cells or associated molecules may provide alternative solutions. “We can now detect when a patient is at risk of developing lifelong allergies and directly target the implicated cells,” said lead author Ahmed Kabil.
This groundbreaking research opens the door to more effective allergy treatments that address the root cause rather than just alleviating symptoms. “This discovery gives us the tools to tackle allergies in a targeted way, potentially preventing their onset or reducing their severity,” said Dr. McNagny.
With these advancements, researchers hope to transform how allergies are managed, moving from symptom relief to long-term solutions that address the underlying mechanisms.