Three main factors define changes in fecal microbiota associated with feeding modality in infants.

Objectives: There are many differences in the fecal infant microbiota associated with various feeding methods. The aim of this study was to examine the major differences in the fecal microbiota of breast-fed (BF) and formula-fed (FF) infants and to describe the principal bacterial components that would explain the variability in the predominant bacterial families and genus clusters.

Methods: Fecal samples from 58 infants, 31 of whom were exclusively BF and 27 of whom were exclusively FF with a standard formula in agreement with the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommendations, were analyzed by fluorescent in situ hybridization combined with flow cytometry.

Assessment of intestinal microbiota of full-term breast-fed infants from two different geographical locations.

The intestinal microbiota in the breast-fed infant is considered as ideally healthy. We assessed the microbiota of breast-fed full-term neonates from two different Spanish locations. Statistically significant geographical differences for different bacterial groups were found, underlining the need to consider and define geographical-related effects on microbiota.