Impact of breastfeeding and formula feeding on immune cell populations and blood cell parameters: an observational study.

Objective: Breastfeeding is associated with improved health outcomes in infancy and throughout adulthood as breast milk encompasses diverse immune-active factors that affect the ontogeny of the immune system in breastfed (BF) infants. Nevertheless, the impact of infant feeding on the immune system is poorly understood, and a comprehensive understanding of immune system development in human infants is lacking. In this observational study, we addressed the effects of different infant feeding approaches on cell populations and parameters in the peripheral blood of infants to gain insight into the innate and adaptive arms of the immune system.

Methods: Using flowcytometric analysis, we performed complete blood counts and immunoprofiling of peripheral blood collected from BF and formula-fed (FF) infants at different ages.

Results: Our results showed that the blood of BF infants had a higher frequency of leukocytes and erythrocytes in early infancy. The hemoglobin concentration was enhanced in BF infants. However, the platelet count was comparable regardless of feeding regimen.

Conclusions: We observed immunophenotypic differences between the two populations of infants, mirrored by improved frequency of innate and adaptive immune cells in BF infants.