Figure 2.

Metabolic signatures according to age and diet. a. Metabolites increased in population receiving Breast Milk (BM). From the 5 metabolites that showed a statistical significant pattern Fumaric (p = 0.011) and 2-ketoglutaric acid (p = 0.012) are shown as representative. b. Metabolites increased in population receiving infant formula (IF). c-f Behavior of representative metabolites according to age (expressed in days) and diet. From the 10 metabolites that showed a statistical significant pattern 3-hydroxy-3-methyl glutaric (p = 0.000) and D-glucitol (p = 0.001) are shown as representative. c-d. Metabolites that show tendency to decrease with age. c. From the three metabolites that showed a statistical significant tendency in both population Lactic acid is shown as representative (p = 0.023). d. From the two metabolites that showed a statistical significant tendency in breast fed population succinic acid (p = 0.028) is shown as representative. e-f. Metabolites that show tendency to increase with age. e. From the five metabolites that showed a statistically significant tendency in both population 3-methyladipic acid (p = 0.013) is shown as representative. f. From the seven metabolites that showed a statistical significant tendency in population receiving infant formula (IF) methylsuccinic acid (p = 0.046) is shown as representative. In all figures Y-axis correspond to arbitrary units (AU) that represent semiquantitative units as defined in methods. Graphical representation of the other metabolites are shown in Figures S1–S3. In silico quantitative metabolic analysis revealed that formula-fed infants increased the excretion levels of metabolites related mainly to amino acid metabolism, fatty acids and carbohydrates (Figure 3). Outstandingly, carbohydrate metabolism was enriched mainly due to the high difference observed in the excretion of Sorbitol (D-glucitol) in urine samples from formula-fed infants.