Effect Partial Digested Triglycerides on Supply Long-chain Fatty Acids to Very Preterm Newborns

Main objective: To determine the bioavailability of long-chain fatty acids in very preterm newborns after administering a supplement from the first days of life until 36 weeks postmenstrual age compared to children who did not receive the supplement. The primary variable will be assessed by measuring the increase in the proportion of docosahexaenoic acid and arachidonic acid in plasma phospholipids. 1 ml of the milk received by the child will be collected to evaluate fatty acid intake naturally at 10, 21 days, and 36 weeks postmenstrual age. Stool samples from the child will also be collected at all time points to evaluate the elimination of the supplement. Secondary objectives: 1. Determine the influence of different polymorphisms (SNPs) on the proportion of fatty acids in plasma phospholipids at birth and after the intervention. This will be evaluated through the analysis of genes related to fatty acid metabolism in buccal mucosa cells. 2. Determine the effect of supplementation on: • Changes in the microbiota from birth to the end of the intervention. • Maturation of brain function. • Brain size. • Lung development. • Growth. Evaluated through: • Metataxonomics • Amplitude-integrated electroencephalography (aEEG) at 34 weeks postmenstrual age (PMA). One channel (P3-P4). aEEG traces were recorded for at least 4 hours using the NicoletOne® EEG system monitor (Natus Medical Inc., CA, United States). The tracings will be evaluated following the maturation scoring system developed by Burdjalov et al. * Cranial ultrasounds (cUS) will be performed at 36 weeks PMA (Canon R, Aplio 500; transducer set at 8-10 MHz). All linear measurements on cUS will be blinded. cUS measurements will be obtained in the following planes: * mid-coronal plane at the level of the foramina of Monro (anterior horn width, ventricular index, ventricle-to-brain ratio, frontal white matter height, interhemispheric fissure and subarachnoid space, coronal atrial plane \[ventricular width at midb