Selenium nanoparticles stabilized by date pulp polysaccharides: Bioactivities, gut microbiota modulation and short chain fatty acids production

Natural polysaccharides confer various physiological functions, including prebiotic qualities, modulation of gut microbiota, and regulation of gut health. This study investigated the green synthesis and characterization of bioactive selenium nanoparticles synthesized from complexation of date pulp residues polysaccharides and sodium selenite (UP-SeNPs). UP-SeNPs were evaluated for in vitro bioactivities, digestion, prebiotic properties, and gut microbiota modulation. Structural analysis indicated UP-SeNPs were crystalline, spherical, evenly distributed (size 91.1 ± 2.34 nm, polydispersity index 0.071, zeta potential -25.24 mV). Compared to controls, UP-SeNPs showed significant dose-dependent radical scavenging activities: 66.8 ± 10.49 % (DPPH), 82.8 ± 1.92 % (ABTS), 495.2 ± 8.94 μg/mL (FRAP), and 981.8 ± 9.09 μg/mL (TAC) at 100 mg/L. Inhibition rates of 82.54 %, 52.97 %, and 39.84 % against α-amylase, α-glucosidase, and ACE, respectively, were noted at 100 mg/L. UP-SeNPs (50 mg/L) showed antiproliferative activities of 34.72 % against Caco-2 and 15.16 % against MCF-7. At 100 mg/L, UP-SeNPs exhibited antibacterial properties against four foodborne pathogens. UP-SeNPs supported the proliferation of standard probiotic strains, evidenced by the high Vmax, reduced lag, and extended exponential phases. Metagenomic analysis indicated that Bifidobacterium adolescentis and other species were abundant. In contrast, metabolomic analysis confirmed pathways for the synthesis of short-chain fatty acids (SCFAs), lipids, carbohydrates, amino acids, and vitamins. These findings may offer a basis for the nanobiotechnological and nanomedical applications of UP-SeNPs.