Gut Glucosinolate Metabolism and Isothiocyanate Production

Abstract

The glucosinolate-myrosinase system in plants has been well studied over the years while relatively little research has been undertaken on the bacterial metabolism of glucosinolates. The products of myrosinase-based glucosinolate hydrolysis in the human gut are important to health, particularly the isothiocyanates, as they are shown to have anticancer properties as well as other beneficial roles in human health. This review is concerned with the bacterial metabolism of glucosinolates but is not restricted to the human gut. Isothiocyanate production and nitrile formation are discussed together with the mechanisms of the formation of these compounds. Side chain modification of the methylsulfinylalkyl glucosinolates is reviewed and the implications for bioactivity of the resultant products are also discussed.

Diverse Excretion Pathways of Benzyl Glucosinolate in Humans after Consumption of Nasturtium (Tropaeolum majus L.)—A Pilot Study

“…When passing onward to the colon, intact GLSs still present can be cleaved by the intestinal microbiota . Depending on the microorganisms that are present in the colon, ITCs, nitriles, or amines are formed . The breakdown products can be resorbed into the blood and again be either metabolized “classically” or excreted via the lungs.…”

Glucosinolate Abundance and Composition in Brassicaceae Influence Sequestration in a Specialist Flea Beetle

“…S3). A chemical reduction of methylsulfinylalkyl GLS, isothiocyanates, and nitriles to the corresponding methylthioalkyl metabolites was previously observed in several bacterial strains, but the functional significance of these metabolic conversions in bacteria and P. armoraciae remains unknown (Luang-In et al 2014;Narbad and Rossiter 2018).…”

BMI Is Associated With Increased Plasma and Urine Appearance of Glucosinolate Metabolites After Consumption of Cooked Broccoli

“…We propose that this difference in plasma levels reflects a difference in response of the colon and associated microbiota to the broccoli glucosinolates. Glucosinolates can be metabolized by gut microbial species including Citrobacter WYE1 and Enterobacter cloacae KS50 (38) and differences in fecal bacterial composition are thought to produce differences in the excretion of glucoraphanin metabolites (23). Furthermore, microbial composition is known to vary between lean and obese individuals, particularly with regard to the ratio of Firmicutes to Bacteroidetes (39,40).…”