The bioavailability, metabolism and microbial modulation of curcumin-loaded nanodelivery systems

Curcumin (Cur), the major bioactive component of turmeric (Curcuma longa) possesses many health benefits. However, low solubility, stability and bioavailability restricts its applications in food. Recently, nanocarriers such as complex coacervates, nanocapsules, liposomes, nanoparticles, nanomicelles, have been used as novel strategies to solve these problems. In this review, we have focused on the delivery systems responsive to the environmental stimuli such as pH-responsive, enzyme-responsive, targeted-to-specific cells or tissues, mucus-penetrating and mucoadhesive carriers. Besides, the metabolites and their biodistribution of Cur and Cur delivery systems are discussed. Most importantly, the interaction between Cur and their carriers with gut microbiota and their effects of modulating the gut health synergistically were discussed comprehensively. In the end, the biocompatibility of Cur delivery systems and the feasibility of their application in food industry is discussed. This review provided a comprehensive review of Cur nanodelivery systems, the health impacts of Cur nanocarriers and an insight into the application of Cur nanocarriers in food industry.