To further define the role of the gut microbiota in the interaction between hepcidin and the antibacterial defense of KCs, we transplanted fecal microbiota from WT or Hamp1–/– donors into antibiotic cocktail (4Abx)–pretreated WT or Hamp1–/– recipients via oral gavage for 10 days before bloodstream E. coli–GFP infection. Here, HAMP is linked to infection.