Abstract:Objective To investigate the association between gut microbiota and clinical indicators in very/extremely low birth weight (V/ELBW) infants within the first 28 days of life. Methods Preterm infants with<32 weeks’gestational age and<1.5 kg birth weight were recruited. Their stool samples were collected on days 1, 14 and 28, and then subjected to 16S rRNA sequencing and LC-MS/MS analysis. The relationship between gut microbiota and metabolites and clinical factors was investigated by Spearman correlation analysis. Results The time to full enteral feeding had the greatest influence on the gut microbiota (r2=0.105, P=0.001). The time to full enteral feeding was positively correlated with Staphylococcus, Dubosiella, Lactobacillus, Faecalibacterium, Acinetobacter johnsonii, Faecalibaculum rodentium, and negatively with Clostridium paraputrificum and Clostridium butyricum (P<0.05). Gut microbiota was positively associated with gestational age and cesarean section on D1, and negatively with positive pressure ventilation time, antibiotic course, and time to full enteral feeding on D14 and D28 (P<0.01). 12-hydroxyoctadecanoic acid, succinic acid, 5-aminopentanoic acid and dodecylbenzene sulfonic acid were negatively correlated with the time to full enteral feeding (P<0.05). Conclusion There is a significant correlation between gut microbiota and metabolites, and clinical indicators. The time to full enteral feeding has the greatest impact on early-stage gut microbiota of V/ELBW infants.