New research has identified a potentially troubling trait in newborn babies that could have long-term implications for their health.
The findings, presented at the European Society of Clinical Microbiology and Infectious Diseases Global 2026, suggest that newborns may already carry antibiotic resistance genes (ARGs) within the first days of life.
Traditionally, a newborn’s gut microbiome was believed to be nearly sterile at birth, with bacteria acquired mainly during delivery or through breastfeeding. However, the new study challenges that assumption, indicating that microbial exposure may begin earlier—possibly during pregnancy.
Researchers examined stool samples from 105 infants admitted to neonatal intensive care units within 72 hours of birth. The analysis revealed the presence of ARGs—genetic elements that allow bacteria to survive antibiotic treatment—in many of the newborns.
Experts warn that this early presence of resistance genes could make certain infections harder to treat later in life, as bacteria may already have the ability to evade commonly used medications.
The study also linked the presence of these genes to factors such as maternal health conditions, hospitalisation during pregnancy, and early medical interventions after birth.
Lead researcher Argyro Ftergioti noted that while some level of resistance was expected, the widespread presence across samples was striking and raises concerns about early-life exposure.
Scientists believe the transfer of resistant bacteria may be influenced by maternal antibiotic use, environmental factors, and early hospital contact.
While gut bacteria play a vital role in developing a child’s immune and digestive systems, researchers stress that maintaining a healthy microbiome is essential for protecting against infections, allergies, and chronic conditions later in life.
They added that further studies are needed to understand the full impact of these findings, while emphasising the importance of infection control and careful antibiotic use in maternal and neonatal care.