Temporal development of the infant gut microbiome

Abstract

The majority of organisms that inhabit the human body reside in the gut. Since babies are born with an immature immune system, they depend on a highly synchronized microbial colonization process to ensure the correct microbes are present for optimal immune function and development. In a balanced microbiome, symbiotic and commensal species outcompete pathogens for resources. They also provide a protective barrier against chemical signals and toxic metabolites. In this targeted review we will describe factors that influence the temporal development of the infant microbiome, including the mode of delivery and gestational age at birth, maternal and infant perinatal antibiotic infusions, and feeding method-breastfeeding versus formula feeding. We will close by discussing wider environmental pressures and early intimate contact, particularly between mother and child, as they play a pivotal role in early microbial acquisition and community succession in the infant.

Keywords: bacteria; gut flora; human milk oligosaccharides; microbiome.

Figure 1.

Stages and associated factors that modulate the microbiome early in life.

Figure 2.

Comparison of bacteria present in the microbiomes of vaginally born and Caesarean-born infants. These ratios show the relative abundances of each species and combine the results of a number of studies.