This is a single-center, open-label, prospective, cohort study of an infant probiotic (Food for Special Dietary Use) conducted in the neonatal intensive care unit (NICU). Each subject enrolled will be in the study from the time of consent (within 10 days of birth) to hospital discharge. A prospective control cohort of 15 infants will initially be enrolled. Fifteen (15) infants will then be enrolled into the B. infantis cohort. Infants in the B. infantis cohort will receive a daily feeding of B. infantis EVC001 in MCT oil until hospital discharge.