Long-term consumption of diets high in fats has detrimental impacts on the immune system, but the window necessary for initiating these effects is unclear. In this issue of Immunity, Xiong et al. demo...

Xiong et al. report that short-term, high-fat diet exposure rapidly alters the gut microbial and immune environment, disrupting tissue homeostasis. IL-22 production by group 3 innate lymphoid cells (I...