Tailoring Smart Oral Nano/Micro Delivery System to Address Multifaceted Gastrointestinal Barriers for Improved Delivery of Food Bioactive Compounds

Bioactive compounds (BCs) have attracted wide attention because of their anti-inflammatory, anticancer, and anti-oxidation activities. In addition, the bioavailability of BCs via oral administration not only concerns the release and degradation during the transition within the enterocoel but also the clearance barrier of mucus and the limited absorption across the human intestine. Encapsulation of BCs in structured smart food delivery systems can effectively solve various gastrointestinal tract (GIT) barriers faced by BCs, which is an area of great interest for food industries. This review discussed the physiological barriers to BC delivery in the GIT, including the gastric and intestinal environment, the mucus barrier, the tight junction (TJ)-associated paracellular route, the epithelium-associated transcellular transport, and the P-glycoprotein efflux pump. Strategies to overcome multiple physiological barriers toward BC delivery through structuring and designing smart delivery systems, for example, tailoring carrier stability, size, surface wettability, surface ligands, surface charge, and co-administration of biomolecules with BCs, are presented. On the basis of the summary of the intelligent delivery system, we put forward the prospect and thinking in order to inspire new delivery systems to ensure that BCs reach the GIT with complete biological activity. This review promoted further research on the design and development of structured delivery systems, which was helpful to increase the practical application of structured delivery systems in food and nutrition.