Impact of Donor Human Milk in the preterm very low birth weight gut transcriptome profile by use of exfoliated intestinal cells

[Background] Own mother’s milk (OMM) is the optimal nutrition for preterm infants. However, pasteurized donor human milk (DHM) is a valid alternative. We explored the differences of the transcriptome in exfoliated epithelial intestinal cells (EEIC) of preterm infants receiving full feed with OMM or DHM.[Methods] The prospective observational study included preterm infants ≤ 32 weeks’ gestation and/or ≤1500 g birthweight. Total RNA from EEIC were processed for genome-wide expression analysis.[Results] Principal component analysis and unsupervised hierarchical clustering analysis revealed two clustered groups corresponding to the OMM and DHM groups that showed differences in the gene expression profile in 1629 transcripts. The OMM group overexpressed lactalbumin alpha gene (LALBA), Cytochrome C oxidase subunit I gene (COX1) and caseins kappa gene (CSN3), beta gene (CSN2) and alpha gene (CSN1S1) and underexpressed Neutrophil Cytosolic Factor 1 gene (NCF1) compared to the DHM group.[Conclusions] The transcriptomic analysis of EEIC showed that OMM induced a differential expression of specific genes that may contribute to a more efficient response to a pro-oxidant challenge early in the postnatal period when preterm infants are at a higher risk of oxidative stress. The use of OMM should be strongly promoted in preterm infants.A.P.-L.: A.G.-R., S.L.-P. and J.K. enjoy research grants CM18/00165, CM16/00174, FI18/0131, CP16/00034 respectively from the Instituto de Investigación Sanitaria Carlos III (Ministry of Science, Innovation and Universities); M.C.C. acknowledges the support from ERC Starting Grant 639226-MAMI from the European Union and also, the Spanish Government of Economy and Competitiveness (MINECO) (AGL2015-707487-P grant). MV a full grant from the RETICS funded by the PN 2018-2021 (Spain), ISCIII- Sub-Directorate General for Research Assessment and Promotion and the European Regional Development Fund (FEDER), reference RD16/0022/0001 and PI17/0131 grant for the IIS Carlos III (Ministry of Science, Innovation and Universities).Peer reviewe