Nonalcoholic fatty liver disease (NAFLD) is considered to be associated with diet and gut dysbiosis. Excessive sucralose can induce gut dysbiosis and negatively affect host health. Maternal diet sh...

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is recognized as the most prevalent chronic liver disease globally. However, its pathogenesis remains incompletely understood. Recent advancements in the gut-liver axis offer novel insights into the development of MAFLD. Polysaccharides, primarily derived from fungal and algal sources, abundantly exist in the human diet and exert beneficial effects on glycometabolism, lipid metabolism, inflammation, immune modulation, oxidative stress, and the release of MAFLD. Numerous studies have demonstrated that these bioactivities of polysaccharides are associated with their prebiotic properties, including the ability to modulate the gut microbiome profile, maintain gut barrier integrity, regulate metabolites produced by gut microbiota such as lipopolysaccharide (LPS), short-chain fatty acids (SCFAs), and bile acids (BAs), and contribute to intestinal homeostasis. This narrative review aims to present a comprehensive summary of the current understanding of the protective effects of polysaccharides on MAFLD through their interactions with the gut microbiota and its metabolites. Specifically, we highlight the potential molecular mechanisms underlying the prebiotic effects of polysaccharides, which may give new avenues for the prevention and treatment of MAFLD.

Background: Both lipid metabolism disorders and inflammation are critical contributors to the progression of metabolic-associated fatty liver disease (MAFLD), yet integrated analyses identifying key genes linking them remain scarce. Methods: Differentially expressed genes in MAFLD were extracted from the GSE135251 dataset and intersected with lipid metabolism- and inflammation-related genes from Molecular Signatures Database (MSigDB). Machine learning on GSE135251, followed by validation on GSE89632, identified key genes. Functional enrichment, immune microenvironment profiling, and nomogram analysis were subsequently conducted. Cellular heterogeneity was assessed using the single-cell sequencing (scRNA-seq) dataset GSE186328, and gene expression in MAFLD mice was validated via real-time Polymerase Chain Reaction (PCR). Activators targeting these genes were predicted using Drug Signatures Database (DsigDB). Results: Four genes—FADS1, FADS2, GLB1, and PNPLA3—were identified as key regulators involved in both lipid metabolism disorders and inflammation in MAFLD. These genes were co-enriched in ribosome-related pathways. GLB1 correlated strongly with CD56dim natural killer cells in immune infiltration analysis. A diagnostic nomogram integrating these genes demonstrated exceptional discriminatory power, with Area Under the Curve (AUC) values of 0.98981 for GSE135251 and 0.9204 for GSE89632. ScRNA-seq revealed elevated FADS1, FADS2, and GLB1 expression in MAFLD-associated NK/T cells compared to controls. Real-time PCR confirmed significant upregulation of all four genes in MAFLD mice. Drug prediction identified estradiol as a potential activator targeting these genes. Conclusions: This study identified FADS1, FADS2, GLB1, and PNPLA3 as key genes involved in the progression of MAFLD, linking metabolic dysfunction and inflammation.

In metabolic dysfunction–associated steatohepatitis (MASH), liver sinusoidal endothelial cells (LSECs) acquire a proinflammatory phenotype termed lipotoxic endotheliopathy. We previously identified glycogen synthase kinase 3β (GSK3β) as a central signaling hub in LSECs during MASH. To elucidate the molecular mechanisms and functional outcome of lipotoxicity-induced GSK3β activation in LSECs, we utilized endothelial cell–specific Gsk3 β -KO ( Gsk3 β ^ΔEnd ) mice fed MASH-inducing diets. Endothelial Gsk3 β deletion significantly reduced markers of lipotoxic endotheliopathy, including adhesion molecules and chemokines, alongside liver injury, inflammation, and fibrosis. Immune profiling via flow cytometry and mass cytometry by time of flight (CyTOF) identified decreased hepatic infiltration of proinflammatory myeloid populations, particularly mature DCs in Gsk3 β ^ΔEnd mice. In a coculture system, GSK3β in lipotoxic LSECs promoted DCs maturation. Mechanistically, GSK3 inhibition restored lipotoxicity-induced alterations in LSEC mitochondrial morphology and respiration by regulating AMP-activated protein kinase and dynamin-related protein 1. This rescue suppressed chemokine and adhesion molecule expression, thereby limiting immune cell recruitment. Collectively, under lipotoxic stress, GSK3β amplifies mitochondrial dysfunction and inflammatory signaling in LSECs, enhancing myeloid cell homing and DC maturation. Targeting LSEC GSK3β may, therefore, represent a promising therapeutic strategy to mitigate LSEC-driven fibroinflammatory response in human MASH.