Lipid-regulatory effects of ultra-high pressure-modified Bangia fusco-purpurea polysaccharides mediated by Akkermansia muciniphila

The effect of ultra-high pressure (UHP)-modified Bangia fusco-purpurea polysaccharides (UBFP) on the growth and metabolic profile of Akkermansia muciniphila, as well as the lipid-regulatory effects of its fermentation products, were investigated. Compared with native BFP, UBFP treated under moderate UHP conditions (200–400 MPa) was found to more effectively promote the growth and polysaccharide utilization of A. muciniphila . In oleic acid-induced HepG2 cells, significant reductions in triglyceride levels and lipid droplet accumulation were observed after treatment with UBFP fermentation products ( p < 0.05), particularly in the UBFP 400 group, which exhibited 12.5% and 20.07% greater reductions than the BFP group, respectively. Metabolomics and proteomics analyses suggested that UBFP fermentation products may influence lipid homeostasis through alterations in lipid-related metabolites and proteins, including hypoxanthine, inosine, FABP3, PLIN4, ALB, FABP4, and SCD5. These alterations were mainly associated with AMPK/ACC-related signaling and several metabolic pathways, including purine metabolism, fatty acid metabolism, and the p53 signaling pathway. These findings provide a theoretical basis for the development of A. muciniphila -mediated algal polysaccharide functional ingredients targeting lipid metabolism.