Abstract: Objective: To address fat malabsorption and associated intestinal dysfunction caused by lipase deficiency, an oral delivery system for Aspergillus oryzae lipase (AOL) was constructed using modified Pueraria lobata (MPL) as the carrier material (AOL@MPL). Methods: MPL was prepared using a microwave-assisted hydrothermal method, and the AOL@MPL system was subsequently constructed using the adsorption method. Mercury intrusion porosimetry, scanning electron microscopy (SEM), and laser scanning confocal microscopy (LSCM) were employed to characterize the pore characteristics, micromorphology, and enzyme adsorption capacity of the system. The catalytic efficacy was evaluated through in vitro catalytic kinetics and the stability was examined in simulated gastrointestinal fluid. Furthermore, the promoting effect of AOL@MPL on fat digestion and absorption in rats gavaged with olive oil and the in vivo safety was assessed by hematoxylin-eosin (HE) staining. Results: MPL exhibited a three-dimensional porous structure with a porosity of 66.98%. In the AOL@MPL system, AOL was adsorbed within the MPL pores, achieving a loading efficiency of (57.91 ± 0.44)%. Compared with free AOL, the AOL@MPL system exhibited significantly enhanced catalytic activity, reaction rate, and substrate affinity toward olive and corn oils (P < 0.001); the activity toward the two substrates increased by 49.6% and 58.0%, respectively. In simulated gastrointestinal fluid, AOL@MPL exhibited superior enzymatic stability compared with free AOL (P < 0.001). In vivo data showed that AOL@MPL significantly elevated serum triglyceride levels (P < 0.05), relieved loose stool symptoms, and reduced fecal fat content in rats gavaged with olive oil (P < 0.05). Additionally, AOL@MPL caused no significant damage to the gastric or intestinal mucosa. Conclusion: The AOL@MPL oral delivery system combines enzyme protection with high efficiency catalysis, exhibiting great potential as a high performance lipase supplement for individuals with fat malabsorption.

Key words: fat malabsorption; Pueraria lobata; Aspergillus oryzae lipase; oral delivery system; enzyme activity