New research has revealed that a newborn's gut microbiome, which was previously thought to be nearly sterile, may be exposed to bacteria during pregnancy. Researchers from the European Society of Clinical Microbiology and Infectious Diseases Global 2026 analyzed stool samples from 105 infants in a neonatal intensive care unit within the first 72 hours of life. They found several genes associated with resistance to commonly used antibiotics, including ones that could enable bacteria to evade antibiotic treatment. The study also identified connections between resistance genes and several maternal and neonatal factors such as maternal hospitalization during pregnancy or central venous catheter placement within the early 24 hours. The findings suggest that a healthy gut microbiome is essential for protection against infections, allergies and future chronic diseases.