The FOUNDATION study will evaluate the tolerability of feeding preterm infants a B. infantis probiotic (EVC001) as the primary endpoint. This particular strain of Bifidobacterium has been shown to uniquely utilize oligosaccharides found in human breast milk, possibly providing a nutritional benefit for the infant consuming breast milk when B. infantis is colonized in the gut.

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.

Inclusion Criteria:

1. Birth weight < 1500 grams or gestational age at birth < 33 and 0/7 weeks
2. ≤ 10 days of life and considered viable
3. Consuming exclusive human milk diet (mother's milk or donor milk) with or without fortifier at time of enrollment
4. Toleration of 1.0 mL bolus enteral feeds

Exclusion Criteria:

1. Presence of septicemia or active infection as determined by positive 48-hour blood cultures
2. Necrotizing enterocolitis
3. Pulmonary hypoplasia
4. Presence of clinically significant congenital heart disease or other major congenital malformation
5. Any infant the Investigator deems to be ineligible for participation