preterm infants

The population of bacteria in premature infants’ guts may depend more on the babies’ biological makeup and gestational age at birth than on environmental factors, researchers at Washington University School of Medicine in St. Louis have found. They discovered that bacterial communities assemble in a choreographed progression, with the pace of that assembly slowest in infants born most prematurely.

Babies born prematurely are surviving in increasing numbers, but many withstand complications of early birth only to suffer late-onset sepsis — life-threatening bloodstream infections that strike after infants reach 72 hours of age. The causes of late-onset sepsis have not been clear. But now, researchers at the School of Medicine led by Phillip I. Tarr, MD, and Barbara B. Warner, MD, have discovered that preterm babies’ guts harbor infectious microbes that can cause this condition.