Gestational-age-dependent development of the neonatal metabolome

Background Prematurity is a severe pathophysiological condition associated with increased morbidity and mortality; however, little is known about the gestational-age-dependent development of the neonatal metabolome. Methods Using an untargeted liquid chromatography tandem mass spectrometry (LC-MS/MS) metabolomics protocol we measured over 6000 metabolites in 148 neonatal heel prick dried blood spots retrieved from the Danish Neonatal Screening Biobank. Using a combination of state-of-the-art metabolome mining tools, including mass spectral molecular networking (GNPS), unsupervised substructure discovery (MS2LDA) and in silico structure annotation, we retrieved chemical structural information at a broad level for over 4000 (60%) metabolites and assessed their relation to gestational age. Results A total of 744 (∼12%) metabolites were significantly correlated with gestational age (false-discovery-rate-adjusted P < 0.05), whereas 93 metabolites were strongly predictive of gestational age, explaining on average 37% of the variance. Using a custom algorithm based on hypergeometric testing we identified 17 molecular families (230 metabolites) overrepresented with metabolites correlating with gestational age ( P < 0.01). Metabolites significantly related to gestational age included bile acids, carnitines, polyamines, amino-acid-derived compounds, nucleotides, dipeptides as well as treatment-related metabolites such as antibiotics and caffeine. Conclusions Carnitines, bile acids, as well as amino acid-derived compounds are known to be affected by the gut microbiota, whereas polyamines such as spermine and spermidine may play an important role in regulating (epithelial) cell growth. Our findings reveal for the first time the gestational-age-dependent development of the neonatal blood metabolome and suggest that gut microbial and gestational-age-dependent metabolic maturation may be monitored during newborn screening.