Effects of colloidal structure in lutein ester gummies on digestive properties and gut microbiota in vitro

Current research on lutein ester gummies primarily focuses on formulation development, with limited studies on how colloidal structures affect digestion and gut microbiota. This study investigated the impact of pectin, gelatin, gellan and carrageenan-based gummies using in vitro digestion and colonic fermentation. Results showed colloidal composition significantly influenced particle size (234–730 μm in stomach; 86–245 μm in intestine) and dispersion coefficients (0.14–0.73 in stomach; 0.12–0.71 in intestine), with pectin increasing and gelatin decreasing these parameters. Particle size and dispersion negatively correlated with lutein ester release. During gastric digestion, these parameters negatively correlated with Subdoligranulum, while viscosity positively correlated with Bifidobacterium. In the small intestine, particle size negatively correlated with Faecalibranulum, Bacteroides, and Allisonella. Gummy consumption increased Muribaculaceae and Lactiplantibacillus, enhancing short-chain fatty acid (SCFA) production. These findings highlight the role of colloidal structure in optimizing lutein ester bioavailability and gut health, providing a basis for targeted food matrix design.