Microbiome Profile Alterations During the First Two Months of Live in Very Low-Weight Preterm Newborns

Over the past decades, bacterial microbiome studies have become increasingly important. The development of the gut microbiome has been shown to play an essential role in human health, and to be especially decisive in infants [1]. It influences nutrient absorption, metabolism regulation, and immune system development. Various factors have been proposed to modulate the development of the microbiome and therefore shape the growth and health of newborns [2]. Premature babies are often lowweight and even more sensitive to health issues. This study aims to analyse the development of the microbiome in preterm neonates over the first two months of life and look for patterns and alterations associated with several factors, like delivery mode, gestation time and necrotizing enterocolitis (NEC). A total of 78 preterm newborns were included in the study, with stool samples being taken at several timepoints from each baby. In total 515 samples were collected. The timepoints varied between ages of one and 61 days and were grouped in six age groups during the analysis. Genomic DNA was extracted from stool samples, and the bacterial V3–V4 hypervariable region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. The data were processed using bioinformatical tools and analysed bioinformatically and statistically to access microbiome composition, abundancies, alpha- and beta-diversities. The analysis revealed significant differences in the bacterial profiles across different timepoints, gestational ages, delivery modes, and in relation to the development of NEC. Alpha diversity indices increased over time; however, fewer or no significant differences were observed between the later timepoints. Consistent patterns emerged from both PCoA and PERMANOVA analyses. Notably, NEC was associated with distinct bacterial. Additionally, the abundance of several bacterial taxa correlated with gestational age. The bacterial profile of premature, low-birth-weight newborns varies according to factors such as age, delivery mode, gestational age, and the presence of disease. Comparing these microbiome dynamics in low-birth-weight infants with those in full-term newborns could provide valuable insights into the development of neonatal diseases such as necrotizing enterocolitis.