News: Probiotic sepsis risk in very preterm infants remains exceedingly low, study reaffirms

Probiotic-associated invasive infections were rare in very preterm infants, according to a large retrospective cohort study from JAMA Network Open.

For this study, researchers evaluated 107,505 very preterm infants with a median gestational age of 30 weeks. Of these infants, 19% were given probiotic supplementation.

Among 613 deaths in infants receiving supplementation, just one occurred more than 30 days after positive blood culture in an infant with invasive infection.

Among the very preterm infants, 11 developed Bifidobacterium or Lactobacillus invasive infections. Eight had been given probiotics (0.04%) while three had not (0.003%), the researchers reported. In overall unmatched and propensity-matched analyses, probiotic supplementation was associated with an absolute increase of 0.04% in Bifidobacterium or Lactobacillus infection (95% CI 0.01-0.06), equivalent to one invasive infection per roughly 2,500 supplemented infants (95% CI 1,667-10,000).

Probiotics given to preterm infants have been shown to reduce the risk of necrotizing enterocolitis, death, and late-onset invasive infection, the researchers explained. "Despite benefits, valid concerns exist about the risk of sepsis from probiotic organisms."

Probiotic-associated sepsis has been reported in case series and case reports, including a systematic review of 16 studies involving 32 preterm infants. The isolated organisms, the researchers acknowledged, were consistent with the most administered probiotic products in preterm infants. These include Bifidobacterium and Lactobacillus strains.

In 2023, the Federal Drug Administration (FDA) issued a warning based on a case report that detailed the risk of invasive disease in preterm infants who were administered probiotics. To date, absolute risks of probiotic-associated sepsis remain uncertain due to the lack of large cohort studies that can be used to systematically estimate uncommon risks, according to the authors.

"Our findings provide clinicians, researchers, families, and regulators with a more reliable estimate of the risk of probiotic-associated invasive infection in preterm infants cared for in U.S. NICUs [neonatal intensive care units]," the researchers noted. "That risk appears to be very low."

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