Education of the human immune system begins in utero via T cell activation and memory development. However, whether part of the education is provided by exposure to microbes in utero remains controversial and unclear. In this issue of Cell, Mishra et al. provide new evidence that the fetal gut may be colonized by bacteria that prime T cell memories.
Copyright © 2021 Elsevier Inc. All rights reserved.
Declaration of interests I.U.M. serves on the Scientific Advisory Board of Luca Biologics. No other conflicts of interest exist.