Decoding the Multi-Component Synergy of Fu Ling Yin Zi for Anti-Oxidative Stress Applications: Formulation Optimization, Molecular Docking, Cell-Based Validation, and 3D-Printed Dysphagia-Friendly Diets

Developing functional foods that address both oxidative stress and physiological challenges like dysphagia is a critical frontier in personalized nutrition. This study investigates the multi-component synergy of Fu Ling Yin Zi (FLYZ), a traditional dietary therapy, and translates its functional properties into a 3D-printed dysphagia-friendly food. Using response surface methodology, the optimal FLYZ formulation was established at a 5:1:5 ratio of Poria cocos (Schw.) Wolf., Amygdalus communis Vas, and Citrus reticulata. Network pharmacology and molecular docking suggested that FLYZ’s active compounds (e.g., nobiletin, stigmasterol, tangeretin, l-SPD, glabridin, estrone) may mitigate oxidative stress via multiple targets (PTGS2, AKT1, TNF, ESR1, MMP9, and MAOA), with pathway analysis pointing to a potential role of the AKT1/GSK3β/HIF-1α axis. Subsequent in vitro cellular assays demonstrated that FLYZ enhanced antioxidant enzyme activities, reduced intracellular ROS, and modulated the expression of associated genes, supporting a potential link to this pathway. To actualize these functional benefits for patients with swallowing difficulties, a novel 3D-printing ink incorporating FLYZ and walnut oil within a hydrogel matrix (3% xanthan gum, 3% pectin, 1.5% carrageenan) was developed. The printed constructs exhibited excellent shape fidelity and, based on standardized IDDSI fork and spoon tests, were categorized as level 4 (pureed/extremely thick). Furthermore, a simulated in vitro digestion model showed that the colloidal network significantly protected FLYZ’s polyphenols and flavonoids, markedly improving their bioaccessibility and post-digestion antioxidant capacity. Collectively, this work establishes an integrated approach that combines predictive molecular profiling with advanced 3D food printing, thereby supporting the development of future foods tailored for personalized nutrition.