Temporal characterization of the gut microbiome and metabolome in preterm infants.

Preterm infants experience abnormal microbial colonization, which coupled with their vulnerable physiology can increase the risk of disease. Understanding the factors influencing the complex relationship between the temporal development of the gut microbiome and functional metabolites derived from microbe-microbe and microbe-host interaction is therefore critical. In this study, 266 longitudinal stool samples from 66 very preterm infants underwent 16S rRNA gene sequencing to analyse gut microbial structure. To further explore the functional status of these gut members, a subset of these samples underwent stool metabolomics (n=101). Statistically significant associations were found with age for both the gut microbiota (P<0.001) and metabolite profiles (P<0.001). Relationships between the gut microbiome and metabolome showed concordance, with 691 significant correlations after adjustment between the top 10 most abundant bacterial taxa and all 977 identified metabolites. Lactobacillus had the highest number of significant correlations (31%), amongst which was a strong positive correlation with equol sulphate, an oestrogen produced by intestinal bacteria. This study reveals consistent relationships between the diet, gut microbiota composition and metabolic function. The findings provide valuable insights into the microbial and metabolic dynamics of the preterm gut and the relationships underlying gut microbiome structure and function in vulnerable preterm infants. Further research is needed to confirm these findings and explore their implications for infant health and development.