Abstract
Background: Premature babies have immature digestive and immune systems and are thus predisposed to gut microbiota dysbiosis. Changes in the microbiota of the gut have been linked to the occurrence of feeding intolerance, necrotizing enterocolitis, and sepsis. Early feeding through the gut is the main factor determining microbial development in neonatal intensive care units. However, there is still little comparative evidence on the effects of mothers own milk, donor human milk, and preterm formula.
Objective: The main aim of this study was to compare gut microbiota composition, predicted functional profiles, and selected clinical outcomes in preterm infants receiving predominantly mothers own milk, donor human milk, or preterm formula during the first three weeks of life.
Methods: This prospective observational cohort study was conducted in a level III neonatal intensive care unit. It recruited 75 preterm infants (<34 weeks gestation, 1, 800 g). Babies were classified into one of three groups according to their feeding type during the first 21 days of life. Stool samples from meconium, day 7, day 14, and day 21 were subjected to 16S rRNA gene sequencing. In addition, clinical outcomes such as feeding intolerance, time to full enteral feeding, necrotizing enterocolitis, and late, onset sepsis were evaluated by analyzing microbial diversity, taxonomic composition, and predicted functional pathways.
Results: Alpha diversity went up over time in all groups, and there were no significant differences between the feeding types. On the other hand, beta diversity significantly differed based on feeding modality on days 14 and 21. Mothers own milk was positively correlated with a higher abundance of Bifidobacterium and Lactobacillus and lower levels of potentially pathogenic taxa. Donor human milk exhibited an intermediate microbial profile, whereas formula feeding was identified by increased Proteobacteria levels. Predicted functional analysis showed increased glycan metabolism in infants fed mothers own milk. Feeding intolerance was the least common, and the time to reach full enteral feeding was the earliest in the mothers own milk group.
Conclusions: The type of early feeding can affect the development of the gut microbiota and feeding tolerance in preterm infants. Mothers own milk helps establish a microbial profile that is more favourable to the infants health, while donor human milk provides benefits that are intermediate when compared with formula feeding.