Metabolomics is the most recent of the omic sciences. Metabolomics can be defined as the quantitative analysis of all the metabolites (small molecules <1 kDa) of a biological sample aiming to the investigation of the multiparametric metabolic response of a living system to pathophysiological stimuli or genetic modifications. A metabolic profile consists of the set of metabolites reflecting enzyme expression and activity, and includes the building blocks and breakdown products of the DNA, RNA, proteins, and cellular components. Also, it is affected by several factors unrelated to the genome, such as interactions with commensal microorganisms, nutritional factors, environmental agents, and any exposure to drugs or toxic substances resulting in discordance between genotype and phenotype. In many fields of medicine, there is a growing interest in characterizing diseases at molecular level with a view to developing an individually tailored therapeutic approach. Metabolomics is a novel area that promises to contribute significantly to the characterization of various disease phenotypes and to the identification of personal metabolic features that can predict response to therapies. Based on analytical platforms such as mass spectrometry or NMR spectroscopy, the metabolomics approach enables a comprehensive overview of the metabolites, leading to the characterization of the metabolic fingerprint of a given sample. These metabolic fingerprints can then be used to distinguish between different disease phenotypes and to predict a drug’s effectiveness and/or toxicity. Several studies published in the last few years applied the metabolomic approach in the field of pediatric medicine. Being a highly informative technique that can be used on samples collected non-invasively (e.g. urine or exhaled breath condensate), metabolomics has appeal for the study of pediatric diseases.

Risk of bronchopulmonary dysplasia in preterm neonates

Preterm delivery (PTD) is a major challenge in the field of obstetrics and neonatology. Since 2006 preterm birth rates have been declining both in the United States and in European countries. Nevertheless, prematurity remains a major cause of morbidity and mortality worldwide, which exceed those of infants born full-term. Preterm neonates are at increased risk of both short- and long-term pathological outcomes and, among these, bronchopulmonary dysplasia (BPD) accounts for the vast majority of cases of chronic lung disease after premature birth. Metabolomics allows simultaneous characterization of low molecular weight compounds and may provide a picture of such a complex condition (PLoS One 2016 Oct 18;11(10):e0164211).

Metabolic perturbations in children with type 1 diabetes

Despite a considerable reduction in diabetes-related complications, including end-stage renal disease, over the past 30 years, individuals with type 1 diabetes (T1D) still exhibit a nearly 3-fold excess mortality as compared with the general population without diabetes, cardiovascular diseases being the leading cause of death in young adults with T1D. While the incidence of T1D is steeply increasing, the age at onset is progressively lowering. An early onset of the disease has been associated to marked morphological alterations of brain morphology and growth. The mechanisms underlying such alterations still remain unexplained. We enrolled children with T1D aged 6-15 years, and healthy peers to investigate the differences in the urine metabolome and to explore the contribution of HbA1c and clinical features to the observed differences (Pediatr Diabetes. 2017 Apr 12. doi: 10.1111/pedi.12524).

Inborn errors of bile acid synthesis are rare genetic disorders that cause chronic liver diseases

Inborn errors of bile acid synthesis are rare genetic disorders of liver metabolism that cause chronic liver diseases, fat malabsorption, and fat-soluble vitamin deficiency during child-hood. These defects, due to a defective functioning of enzymes, are characterized by a failure to produce normal bile acids (BAs) and an accumulation of unusual BAs and BAs intermediates. BAs are potent digestive surfactants that promote the absorption of cholesterol, lipids and fat-soluble vitamins acting as emulsifiers. They provide the primary driving force for the promotion and secretion of bile and are essential for the development of the biliary excretory route for the elimination of endogenous and exogenous toxic substances, including bilirubin, xenobiotics, and drug metabolites. Early diagnosis of inborn errors of BAs synthesis is important because if the disorder remains untreated, progressive liver disease, together with neurologic disease, may develop and lead to death or require liver transplantation.