Metagenomic Analysis Reveals Alterations in the Gut Microbiome of Preterm Infants with Extrauterine Growth Restriction.

Significant differences in gut microbial community composition were observed between EUGR and AGA preterm infants as evidenced by the Bray-Curtis dissimilarity index.

• 62 preterm infants hospitalized in the NICU at Guangdong Women and Children Hospital were enrolled
• EUGR group: n = 34; normal growth (AGA) group: n = 28
• Fecal samples were collected at one month postnatally
• Total bacterial DNA was extracted and sequenced using the Illumina HiSeq X Ten system
• Bray-Curtis dissimilarity index was used to evidence community-level differences

The EUGR group exhibited a notable increase in Klebsiella pneumoniae and Enterococcus faecalis compared to the AGA group.

• Both Klebsiella pneumoniae and Enterococcus faecalis were significantly more abundant in EUGR infants
• These differences were identified through metagenomic sequencing analysis
• These taxa were among the discriminatory microbial features between groups

The EUGR group showed a significant decrease in Streptococcus raffinosi, Rothia mucilaginosa, Parabacteroides merdae, and Eggerthella lenta compared to the AGA group.

• Four bacterial species were significantly reduced in EUGR infants relative to AGA infants
• These species were identified through metagenomic sequencing of fecal samples collected at one month postnatally
• These reductions represent potential microbial signatures associated with impaired growth

Functional annotation of metagenomic genes identified 415 genes with significantly different relative abundances between the EUGR and AGA groups.

• 415 genes showed significantly different relative abundances between groups
• Functional annotation was performed on metagenomic gene sequences
• A classification model incorporating five discriminatory genes achieved effective separation of EUGR from AGA infants
• The five-gene model demonstrates potential diagnostic utility for identifying EUGR

The EUGR group exhibited a higher relative abundance of antibiotic resistance genes compared to the AGA group.

• Antibiotic resistance gene abundance was assessed through metagenomic sequencing
• EUGR infants had greater antibiotic resistance gene burden than normally growing AGA infants
• This finding adds to the characterization of the gut microbiome alterations in EUGR preterm infants