Gut Microbiome Composition of Preterm Infants with Necrotizing Enterocolitis in American and Brazilian Populations

Background: Necrotizing enterocolitis (NEC) is a devastating intestinal disease that affects preterm infants and remains a leading cause of morbidity and mortality in this population. The gut microbiome has been implicated in the pathogenesis of NEC, and the taxonomic composition can vary depending on several factors, including geography. This study aims to compare the gut microbiome composition and abundance in preterm infants with NEC from the United States and Brazil to explore the impact of geography and ethnicity. Methods: This cohort study included forty-three (43) fecal samples from twenty- one (21) preterm infants with NEC from the United States USA and Brazil. A 16S rRNA amplicon profiling approach was conducted on extracted fecal DNA to characterize the gut microbiome composition and abundance of those NEC infants. The inclusion criteria were preterm infants with a confirmed diagnosis of NEC, birth weight between 440 g and 2101 g, gestational age under 34 weeks, and neonatal antibiotic exposure. The exclusion criteria were children with complex congenital cardiopathy or spontaneous intestinal perforation without radiological evidence of NEC. Taxonomic and statistical analyses were conducted via the EzBioCloud platform to identify the differences in gut microbiome composition and abundance between the infants from these 2 countries. Results: Differences in gut microbiome composition and abundance between NEC-preterm infants in the United States and Brazil has been demonstrated. The USA group had a higher abundance of Pseudomonadota and a lower abundance of Actinobacteria and Bacteroidetes, while the Brazil group had a higher abundance of Firmicutes and a lower abundance of Proteobacteria. At the genus level, Staphylococcus was most predominant in the USA group, while Bacteroides and Prevotella were most predominant in Brazil. Conclusion: The study findings revealed significant compositional and abundance differences in the gut microbiome of NEC-preterm infants between the USA and Brazil, suggesting geographical and ethnicity variations impact on the gut microbiome of NEC infants. This study will help improve our understanding of NEC pathogenesis and the development of targeted interventions, taking in consideration the geographical and ethnic specificities of the subjects.