Abstract: The invention pertains to a composition for use in increasing the relative abundance of Bacteroides and Parabacteroides in the intestinal microbiota of an infant that was delivered by Caesarean section or of an infant that was exposed to antibiotics early in life (e.g. intrapartum antibiotic prophylaxis (IAP)), preferably an infant that was delivered by Caesarean section, wherein the composition comprises Bifidobacterium breve and non-digestible oligosaccharide(s).

Abstract: The invention provides a method, system, and computer program product for determining a maturation state of an infant aged between 0 and 120 months, comprising measuring at least one microbial biomarker from a set of measurable microbial biomarkers from a faecal sample of the infant, determining a predicted age of the infant based on the at least one microbial biomarker, wherein the at least one microbial biomarker is selected from the set of measurable microbial biomarkers based on an analysis of the set of measurable microbial biomarkers as measured in faecal samples from a plurality of vaginally-born breast-fed infants at a plurality of ages, the predicted age is obtained based on an evaluation of the at least one measured microbial biomarker using a function based on a plurality of corresponding at least one biomarkers measured in the faecal samples from the plurality of vaginally-born breast-fed infants at the plurality of ages.