Bloodstream infections in preemies may originate from their gut microbiomes

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Dangerous bacterial bloodstream infections in preemies may originate from the infants’ gut microbiomes, according to researchers at Washington University School of Medicine in St. Louis. Such infections are of substantial concern, as about half of infants who are extremely preterm or have very low birth weights experience at least one episode of the life-threatening infection after 72 hours of life.

The findings are published May 3 in the journal Science Translational Medicine.

Preterm infants are at high risk of infections due to underdeveloped organs, coupled with considerable antimicrobial exposure. Until recently, virtually every prematurely born baby was treated with antibiotics as a preventive measure. While the antibiotics are intended to target disease-causing pathogens, this treatment also can lead to disruption of the gut microbiome in a way that could allow virulent strains of antibiotic-resistant bacteria to increase in numbers.

“This is a vulnerable population,” said senior author Gautam Dantas, PhD, the Conan Professor of Laboratory and Genomic Medicine and a professor of pathology & immunology. “This is also a time when the composition of the gut microbiome is first developing. These early exposures to bacteria shape the gut microbiome in ways that will probably stay with these babies for the rest of their lives. We also have studied the gut microbiomes of infants born at full term, and we know that such babies do not have as many problems, but it’s clear that the type of bugs that colonize the gut in the first few months to three years of life will determine what the microbiome looks like later on. Our study also suggests that an early look at the gut microbiome in preemies may allow us to identify those at high risk of dangerous bloodstream infections.”