Dynamic viral and bacterial ecology of the infant gut. STLInfantTwins

The early years of life are important for an infant’s health and development. While it has been established that the gut bacterial microbiome is rapidly acquired after birth, much less is known about the viral microbiome (virome) – collectively consisting of bacteriophages and eukaryotic RNA and DNA viruses – during the first years of life. Here, we defined the gut virome and bacterial microbiome of a longitudinal cohort of healthy infant twins. We demonstrate that the virome and bacterial microbiome are more similar between co-twins than between non-related infants. Infant development was marked by an expansion in the eukaryotic virome and the bacterial microbiome, whereas there was a contraction and shift in bacteriophage virome composition. We show that the bacteriophage-bacteria relationship begins from birth with a “high predator-low prey” dynamic, consistent with the Lotka-Volterra “predator-prey” model. Thus, in contrast to the stable microbiome observed in adults, the infant microbiome is highly dynamic.