Researchers Link Early Antibiotic Use to Lasting Immune Changes

A study from the University of Rochester Medical Center has found that exposure to antibiotics early in life can impair the development of an infant’s immune system, but a naturally occurring molecule called inosine may help reverse this effect. Published in Cell, the research examined both mouse models and human infant lung tissue to explore how antibiotics given during pregnancy and infancy can weaken the immune system’s ability to fight respiratory infections such as the flu.

The researchers discovered that antibiotics disrupt the gut microbiome’s production of inosine, a molecule described by senior author Hitesh Deshmukh as “a molecular messenger” that travels from the gut to developing immune cells, guiding their maturation and preparation for future infections. When mice were supplemented with inosine, the damage to the immune system caused by antibiotics was largely corrected, suggesting a possible therapeutic strategy for vulnerable infants.

The study was part of a long-term NIH-funded initiative to investigate how early-life exposures affect lifelong disease risk. Deshmukh explained, “We know that antibiotics can be lifesaving for infants, but they also disrupt the microbiome during a critical window of immune development. Our study identifies one way that disruption affects lung immunity, and more importantly, a way to potentially fix it.” The disruption impacts the formation of tissue-resident memory T cells, which are essential for long-term protection against viral infections in the lungs. Without these cells, infants may remain susceptible to severe respiratory illnesses into adulthood.

Using samples from the BRINDL biobank, the team confirmed similar immune deficits in human infants exposed to antibiotics. Most importantly, inosine supplementation restored the development of functional memory T cells in mice. Deshmukh emphasized the importance of further research, noting that these findings could inform future interventions to help newborns build stronger immune memory while balancing the necessary use of antibiotics.