Weijuan Han, Peipei Fu, Hong Cui
NICU extremely preterm infants presented distinct gut microbiota structure at multiple taxonomic levels relative to term infants. Their microbial profiles tended to converge within 4 weeks but remained unique. Sphingomonas was identified as an unvalidated candidate marker needing further verification.
BACKGROUND: Early‑life gut microbiota shapes neonatal health. Extremely preterm infants frequently experience gut dysbiosis, while relevant Chinese longitudinal data remain scarce. This study aimed to explore early gut microbiota dynamics and identify potential microbial markers in Neonatal Intensive Care Unit (NICU) extremely preterm infants.
METHODS: Infants with gestational age ≤32 weeks admitted to the NICU of Beijing Friendship Hospital, Capital Medical University from June 2019 to December 2021 were enrolled, with full-term breastfed infants as controls. Clinical data and stool samples at postnatal <3 days, 2 weeks and 4 weeks were collected for 16S ribosomal ribonucleic acid (16S rRNA) sequencing to analyze gut microbiota composition and temporal variations.
RESULTS: A total of 34 extremely preterm and 17 term infants were included. Baseline characteristics including gender, delivery mode and prolonged rupture of membranes (PROM) (>18 h) were comparable between groups. Alpha diversity remained stable over time in term infants, while it was markedly higher within 3 days after birth than at 2 and 4 weeks in extremely preterm infants. Extremely preterm infants had higher early alpha diversity than term infants, with no intergroup differences thereafter. Principal coordinate analysis (PCoA) revealed obvious beta diversity temporal disparities in both groups. Compared with term infants, extremely preterm infants showed enriched colonization of Enterococcus, Streptococcus and Sphingomonas, along with delayed colonization of Enterobacter, Bifidobacterium and Bacteroides. Random forest analysis screened Sphingomonas as a candidate characteristic microbial genus of NICU extremely preterm infants.
CONCLUSIONS: NICU extremely preterm infants presented distinct gut microbiota structure at multiple taxonomic levels relative to term infants. Their microbial profiles tended to converge within 4 weeks but remained unique. Sphingomonas was identified as an unvalidated candidate marker needing further verification.