Within months of birth, some pathogens are detectable in infants’ guts

The guts of newborns are colonized by detectable viruses as soon as the first month after birth, according to a new study. The human microbiome is typically associated with bacteria, but the collection of microbes also includes viruses and fungi. Researchers behind the work tested stool samples from 125 4-month-old babies in the U.S., and found, in general, that two different types of viruses had colonized many of their guts, some of which could be infectious. Those babies who had been breastfed were less likely to harbor pathogenic viruses, whereas around 30% of the babies who had been given formula harbored viruses known to infect people — even though the formulas themselves didn't reveal the presence of any viruses. Still, findings only show an association and shouldn't change much for parents, writes STAT's Kate Sheridan in a new story for STAT Plus subscribers.