The Landscape of Influential Factors on Fecal Calprotectin in Convalescing Preterm Infants (Corrected Age of 10-18 Months)

Purpose To investigate the factors affecting fecal calprotectin in preterm infants at the corrected age of 10–18 months. Methods This research employs a cross-sectional design. Infants with a gestational age of less than 37 weeks were recruited at a corrected age of 10 to 18 months (born between April 2023 and April 2024) from the Child Healthcare Department of Suzhou Hospital Affiliated to Nanjing Medical University between June 2024 to August 2024. The fecal calprotectin was measured and was classified into three grades: < 15µg/g, 15–60µg/g/g, and > 60µg/g. Relevant information was collected. Results Fecal calprotectin levels in preterm infants who received formula supplementation before 6 months of corrected age were lower than those in infants who received it after 6 months. In convalescent preterm infants with constipation, fecal calprotectin levels exhibit a mild elevation, typically below 60 µg/g. Probiotics demonstrate a more pronounced effect on improving fecal calprotectin grades rather than content. Conclusions Compared with non-exclusively convalescing preterm infants within the corrected age of 6 months, those who were exclusively breastfed showed increased intestinal inflammation mediated by neutrophils. Constipation moderately elevates the fecal calprotectin levels. Probiotics may serve as a protective factor against a lower degree of neutrophil-mediated intestinal inflammation. During early gastrointestinal development, long-term, low-grade, and safe inflammatory stimulation may be a positive factor for intestinal barrier development.