Kevin Brown

Scope The glucosinolate glucoraphanin from broccoli is converted to sulforaphane (SFN) or sulforaphane‐nitrile (SFN‐NIT) by plant enzymes or the gut microbiome. Human feeding studies typically observe high inter‐individual variation in absorption and excretion of SFN, however, the source of this variation is not fully known. To address this, a human feeding trial to comprehensively evaluate inter‐individual variation in the absorption and excretion of all known SFN metabolites in urine, plasma, and stool, and tested the hypothesis that gut microbiome composition influences inter‐individual variation in total SFN excretion has been conducted. Methods and Results Participants ( n = 55) consumed a single serving of broccoli or alfalfa sprouts and plasma, stool, and total urine are collected over 72 h for quantification of SFN metabolites and gut microbiome profiling using 16S gene sequencing. SFN‐NIT excretion is markedly slower than SFN excretion (72 h vs 24 h). Members of genus Bifidobacterium , Dorea , and Ruminococcus torques are positively associated with SFN metabolite excretion while members of genus Alistipes and Blautia has a negative association. Conclusion This is the first report of SFN‐NIT metabolite levels in human plasma, urine, and stool following consumption of broccoli sprouts. The results help explain factors driving inter‐individual variation in SFN metabolism and are relevant for precision nutrition.