RecruitingHeme and Non-heme Iron Intakes, Gut Microbiota, and Influence on Host Iron AbsorptionThe FeMicrobiome study will evaluate gut microbiome features and their relationships with dietary iron absorption in healthy adults. The investigators hypothesize that (1) the gut microbiota can be shaped by the heme and non-heme Fe content of the diet and that (2) this will influence individual variation in dietary Fe absorption.