Inclusion Criteria:  Babies with birth weight ≤ 1500 g  Exclusion Criteria:  Babies who have any contraindication for initiating milk feeds; who will fail to achieve adequate feed volume to be able to administer the study drug. Those with suspected/ proven gastrointestinal malformations. Preexisting sepsis (definite or suspect) or NEC at the time of enrollment. Those with a family history of an inborn error metabolism (that precludes exposure to proteins/lactose).