Bifidobacterium longum subsp. infantis EVC001 Administration Is Associated with a Significant Reduction in the Incidence of Necrotizing Enterocolitis in Very Low Birth Weight Infants

Objective To assess the effects of Bifidobacterium longum subsp. infantis EVC001 (B infantis EVC001) administration on the incidence of necrotizing enterocolitis (NEC) in preterm infants in a single level IV neonatal intensive care unit (NICU). Study design Nonconcurrent retrospective analysis of 2 cohorts of very low birth weight (VLBW) infants not exposed and exposed to B infantis EVC001 probiotic at Oregon Health & Science University from 2014 to 2020. Outcomes included NEC incidence and NEC-associated mortality, including subgroup analysis of extremely low birth weight (ELBW) infants. Log-binomial regression models were used to compare the incidence and risk of NEC-associated outcomes between the unexposed and exposed cohorts. Results The cumulative incidence of NEC diagnoses decreased from 11.0% (n = 301) in the no EVC001 (unexposed) cohort to 2.7% (n = 182) in the EVC001 (exposed) cohort (P < .01). The EVC001 cohort had a 73% risk reduction of NEC compared with the no EVC001 cohort (adjusted risk ratio, 0.27; 95% CI, 0.094-0.614; P < .01) resulting in an adjusted number needed to treat of 13 (95% CI, 10.0-23.5) for B infantis EVC001. NEC-associated mortality decreased from 2.7% in the no EVC001 cohort to 0% in the EVC001 cohort (P = .03). There were similar reductions in NEC incidence and risk for ELBW infants (19.2% vs 5.3% [P < .01]; adjusted risk ratio, 0.28; 95% CI, 0.085-0.698 [P = .02]) and mortality (5.6% vs 0%; P < .05) in the 2 cohorts. Conclusions In this observational study of 483 VLBW infants, B infantis EVC001 administration was associated with significant reductions in the risk of NEC and NEC-related mortality. B infantis EVC001 supplementation may be considered safe and effective for reducing morbidity and mortality in the NICU.