Sulforaphane and Sulforaphane‐Nitrile Metabolism in Humans Following Broccoli Sprout Consumption: Inter‐individual Variation, Association with Gut Microbiome Composition, and Differential Bioactivity

Abstract

ScopeThe 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 ResultsParticipants (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.ConclusionThis 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.

Identification of biological signatures of cruciferous vegetable consumption utilizing machine learning-based global untargeted stable isotope traced metabolomics

“…Biological samples (urine and plasma) were collected from two different human feeding studies that were previously published: (1) broccoli sprouts feeding study (includes a non-cruciferous vegetable control arm where participant consumed alfalfa sprouts) (NCT04641026) ( 29 ), and (2) collard greens feeding study with collard greens as a source of phylloquinone (vitamin K) (NCT00336232) ( 30 ). We also utilized the vegetable material from these studies to train our machine learning approach.…”

“…For the broccoli study, thirty two healthy women and men, 19–55 years old, were recruited in Corvallis, Oregon ( 29 ). The study was conducted in the Linus Pauling Institute and the Moore Family Center metabolic kitchen between April and November 2021.…”

“…Participants in the broccoli arms consumed fresh broccoli sprouts (40.5 g on average) containing 100 μmol sulforaphane equivalents. Sulforaphane contents in broccoli sprouts were analyzed on the day of harvest for every cohort as previously described ( 29 ). The alfalfa sprout dose was equivalent in weight to the amount of sprouts consumed by the broccoli sprout participants.…”

Reply to Curtis, L. Comment on “Magner et al. Sulforaphane Treatment in Children with Autism: A Prospective Randomized Double-Blind Study. Nutrients 2023, 15, 718”

“…Glucosinolate metabolism was shown to exhibit high levels of inter-individual variation for metabolite production in plasma, urine, and stool samples in ASD patients. Personalized differences in microbiome composition are assumed to underly the glucosinolate metabolism variations [ 8 ]. Thus, the unified effects of phytonutrient supplementation in the environment of highly variably dysregulated gut microbiome of ASD patients seem to be unlikely.…”