The Gut Microflora of the Developing Infant: Microbiology and Metabolism

Abstract

The colonization of the infant gut after birth represents a complex succession of bacterial types and is governed by a wide range of external influences such as the mother’s vaginal, faecal and skin floras, the extent of bacterial contamination of the perinatal environment and the feeding regime. The influence of breast feeding and formula feeding on the development of the infant gastrointestinal tract (GIT) microflora has been the subject of numerous studies that have often yielded conflicting results. Earlier studies have reported differences between breast- and formula-fed infants, and in particular that breast-fed infants have a microflora dominated by bifidobacteria. These differences, evident in early comparisons of breast- vs formula-fed infants, appear to have diminished, most probably as a consequence of factors including changes in obstetric practices and environment, advances in bacterial identification and methodology and improvements in formula feeds.