Alginate oligosaccharide (AOS), a degradation product of alginate derived from marine brown algae, has attracted significant attention due to its potent ability to modulate gut microbiota and enhance human health. This review aims to systematically introduce current evidence on the interactions between AOS and gut microbial communities, focusing on how AOS improves health through regulating gut microbiota. Initially, the structural factors of AOS that influence their functions are highlighted, including molecular weight, monomer composition, terminal structure, and chemical modifications. Importantly, AOS primarily exerts beneficial effects by adjusting gut microbiota community and outputs, which include the promotion of probiotics, the inhibition of pathogens, the balance of microbiota composition, and the increase of short-chain fatty acid production. Moreover, the discovered mechanisms underlying AOS-mediated health promotion via microbiota modulation are detailed comprehensively, specifically emphasizing intestinal barrier maintenance, antioxidation, dual-regulation of immune and inflammatory responses, pathogenic infection inhibition, metabolic improvement, uric acid excretion promotion, anti-tumor effects, and anti-skin aging. Such beneficial effects make AOS valuable in keeping healthy, preventing disorders, and intervening in diseases. Despite these findings and research progress, there are yet limitations in studying AOS–gut microbiota interactions, such as precise microbiota-targeted structural optimization, personalized nutritional interventions based on microbial characteristics, and broadening the horizon of microbiota-derived metabolic metabolomic profiles. In conclusion, advancing our understanding of the gut microbiota-centered mechanisms of AOS would probably facilitate novel nutritional strategy development for health promotion.

Plasmalogens, as natural dietary lipids, are a unique class of glycerophospholipids with distinct structural and functional properties. They are unstable due to the vinyl ether linkage and the unsaturated fatty chains. Hence, plasmalogen changes are closely connected to their beneficial bioactivities and health-related applications. This narrative review focuses on their structural modifications, particularly oxidation of the vinyl-ether and sn-2 acyl chains, enzymatic degradation, and molecular remodeling. The oxidative susceptibility of plasmalogens renders them particularly vulnerable under inflammatory or oxidative stress, contributing to a measurable reduction in total plasmalogen content. Plasmalogen deficiency has been observed in various diseases and applied in clinical applications, including physiological and a variety of pathological conditions. Moreover, plasmalogens have been recognized as not only disease biomarkers but also therapeutic targets. In addition, recent findings in nutrition were discussed, aiming to find that underutilized animal byproducts and microbial lipids are promising new sources of plasmalogens. To conclude, it is crucial to establish practical dynamic monitoring systems of plasmalogens for health promotion and disease prevention interventions. Integrating biochemical pathways, clinical diagnosis, and nutritional interventions remains to be clarified.