Dual mechanisms of digestion-resistant proteins in food systems: structural resistance and enzyme inhibition

Digestion-resistant proteins, which are proteins that reduce or inhibit the digestive process of dietary nutrients, might be an emerging field to explore. Growing public interest in food composition and health has drawn attention to digestion-resistant proteins, yet their functional roles and mechanisms remain poorly understood. While consumers increasingly recognize the impact of dietary components like resistant starch, proteins that evade digestion have not been systematically studied. This review summarizes the current understanding of the various forms of digestion-resistant proteins found in natural food products, and addresses the challenges associated with elucidating their mechanisms of action. It is clarified that the dual mechanisms of their resistance to digestion could attribute either to intrinsic structural stability or through inhibiting digestive enzymes as protein-based inhibitors. Collectively, these proteins can serve diverse functions, including modulating nutrient absorption, influencing postprandial glycemic responses, and promoting gut health. Furthermore, there is an urgent need to consider potential safety concerns related to development of food products and therapeutics containing significant levels of resistant proteins and protein-based digestive enzyme inhibitors.