Alteration of Stool Microbiota in Preterm Infants With Anemia

Necrotizing enterocolitis (NEC) is a leading cause of death in preterm infants, yet the
disease mechanism is not well understood. Among the factors that have been studied are the
change in stool microbiota (dysbiosis), severe anemia, and transfusion. Studies suggest that
dysbiosis occurs in neonates with NEC. Large studies and meta-analyses have shown a
predominance of Gammaproteobacteria, a decrease in Firmicutes, and decreased bacterial
diversity in stool from infants with NEC. Studies do not support a relationship between
transfusions and NEC since there are conflicting findings on this topic. There is a
suggestion, however, that severe anemia may be associated with NEC though this requires
further study.

No studies have been done evaluating the relationship between anemia and change in stool
microbiota, or blood transfusion and change in stool microbiota. This study aims to primarily
evaluate the relationship between anemia and stool microbiota, and secondarily evaluate the
relationship between transfusion and stool microbiota.

Inclusion Criteria:

- Preterm infants less than 32 weeks gestation at birth

- Age at enrollment between 7 days and less than/equal to 30 days

- Minimum 100 mL/kg/day enteral feeds

Exclusion Criteria:

- Development of necrotizing enterocolitis (NEC) prior to enrollment

- Prior surgery

- Major congenital anomalies

- Oxygen requirement with FiO2 (fraction of inspired oxygen) >50% (at time of
enrollment)