Microbiota: a mediator to transform glucosinolate precursors in cruciferous vegetables to the active isothiocyanates.

Isothiocyanates (ITCs), such as sulforaphane (SFN), exhibit powerful biological functions in fighting cancers, and cardiovascular and neurodegenerative diseases. They normally exist as glucosinolates (GLSs) in cruciferous vegetables, which are not themselves bioactive until they are degraded by myrosinase to form ITCs. Myrosinase coexists in the same plants but is normally kept apart from GLSs in different apparatus. A key point is that myrosinase is temperature sensitive and can be inactivated upon exposure to temperatures over 60 °, as typically occurs during cooking. However, studies using animal models and population trials have suggested that human gut bacteria might act like an 'organ' in that they can secrete their own myrosinase. In this review, the hydrolysis of GLS by myrosinase is discussed, with an important focus on the gut microflora and their myrosinase-producing roles.