Assessment of the Impact of Type of Probiotic, Delivery Type and Feeding Type on Baby's Microbiota After Dysbiotic Delivery

Inclusion Criteria: * Healthy infants up to 25 days of life * Infants with adequate weight according to the gestational age. * Infants born by vaginal delivery whose mother was given antimicrobial prophylaxis or infants born by C-section. * Gestational birth equal or greater than 37 weeks. * Exclusive or almost exclusive breastfeeding (understanding almost exclusive the one in which there is a maximum of one formula feeding per day) or mixed feeding (in which there is more than one formula feeding per day). Exclusion Criteria: * Infants with smoker mother during pregnancy and after delivery. * Infants whose parents cannot follow the study requirements * Infants who have suffered neonatal admission or have suffered or suffer necrotizing enterocolitis, infectious disease, congenital malformation, short bowel syndrome or any serious illness. * Infants who have taken probiotics before the start of the trial or who take formula with probiotics. * Breast-fed infants whose mothers have taken probiotics within the two weeks before study inclusion. * Infants who ingest special formulas as extensively hydrolysed formulas. * Breast-fed infants whose mothers have excluded dairy products and egg products in their diet during breastfeeding * Infants who take specific medication for the treatment of functional digestive disorders: antacids (type IBP or H2 blockers), laxatives (PEG, lactulose, magnesia), lactase and simethicone at the time of inclusion. * Infants undergoing therapies with…