523 - Human Milk Fortification and Intestinal Inflammation in Very Preterm Infants

Poster Number: 523
Publication Number: 523.1896

Background: Fecal calprotectin is elevated in necrotizing enterocolitis (NEC), which may represent the extreme of a spectrum of intestinal inflammation. Prior studies report differing associations between diet and fecal calprotectin. Fortification of human milk is often used to enrich the nutrient content of human milk, but there is limited data on how different approaches to fortification influences intestinal inflammation.

Objective: The purpose of this study was to evaluate the association between bovine or human milk-derived fortifiers on fecal calprotectin in very preterm infants.

Design/Methods: We conducted a retrospective analysis of data from a prospective cohort study of very preterm infants with a birth weight <= 1250 grams from 2017-2021 recruited at 3 hospitals in Atlanta, Georgia. Fecal calprotectin was measured weekly in stool using an enzyme-linked immunosorbent assay. Diet information, including base diet, fortification, and volume of intake was collected daily. The analysis data set was limited to fecal calprotectin measurements in the subsequent week after an infant had fortification of human milk with either a bovine-derived or human milk-derived fortifier. Multivariable models accounting for within infant correlation, baseline calprotectin levels, total intake volume, and receipt of transfusion were used to evaluate subsequent increases in log-transformed fecal calprotectin levels. As a secondary aim, we evaluated whether red blood cell transfusion modified the relationship between human milk fortifier and calprotectin levels.

Results: We analyzed 478 separate feeding and weekly fecal calprotectin observations from 135 infants who received fortified human milk. The median birth weight of the cohort was 916 grams (25th – 75th percentile: 780 – 1086) and the median gestational age was 27.3 weeks (26.3 – 28.5). Of 478 feeding observations, 59 (12%) were with bovine-derived fortification, compared to 419 (88%) from human-milk derived fortification. On multivariable analysis with bovine-derived fortification as a reference group, infants receiving human milk fortification with a human-derived fortifier had a lower log fecal calprotectin in the subsequent week of measurement (-0.23; 95% CI, -0.46 to -0.00, P= 0.048, Figure 1). Red blood cell transfusion did not appear to modify this relationship (interaction P=0.27).

Conclusion(s): Human milk fortification with a human milk-derived fortifier is associated with decreased intestinal inflammation measured by fecal calprotectin in very preterm infants.