A new study has shown that hardship experienced by mothers during their own childhood or during pregnancy is reflected in the composition of their 2-year-old children's gut microbiome. It was previously understood that in rodents, prenatal stress affects microbiomes into adulthood, but how long after birth the effects lasted in humans was unknown. The changes to this community of microorganisms are likely among the ways that hardship affects a child's socioemotional development.