Saturated alginate oligosaccharide as a new functional food: preparation, characterization and alleviation of cognitive impairment through pre-intervention.

In this study, sodium alginate was used as the raw material to prepare alginate oligosaccharides via the acid hydrolysis method. Structural characterization was conducted via high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS), and nuclear magnetic resonance (NMR) spectroscopy. The results indicated that the prepared alginate oligosaccharide product was a type of saturated alginate oligosaccharides (SAOS) with a degree of polymerization ranging from 2 to 10. Dietary SAOS administration significantly ameliorated scopolamine-induced memory impairment in animals. Mechanistically, SAOS enhanced acetylcholine synthesis by modulating cholinergic enzymes and alleviated oxidative stress by reducing malondialdehyde and elevating superoxide dismutase. Additionally, SAOS ameliorated the scopolamine-induced reduction in Roseburia abundance. Non-targeted metabolomics revealed that SAOS reversed the scopolamine-induced decrease in the N-arachidonoyl dopamine level in serum and the linoleoyl ethanolamide level in the cerebral cortex. Collectively, SAOS prevents and improves mild memory impairment, offering a promising nutritional strategy for managing mild cognitive impairment.