Scytosiphon lomentaria Fucoidan Ameliorates Glucose and Lipid Abnormalities via Modulation of the Microbiota-Gut-Liver/Pancreas Axis: Insights from Multiomics Analysis.

FUC2 is a homogeneous acidic heteropolysaccharide with a specific structural composition including fucose-, mannose-, and galactose-rich regions.

• FUC2 was purified from Scytosiphon lomentaria and structurally characterized
• The polysaccharide is mainly composed of fucose-, mannose-, and galactose-rich regions
• FUC2 contains possible glycosidic linkages as part of its structural characterization
• FUC2 was described as a homogeneous acidic heteropolysaccharide

FUC2 attenuated insulin resistance and oxidative stress by activating the AMPK and Nrf2 signaling pathways in mice.

• FUC2 administration improved glucose and lipid metabolism in a mouse experimental model
• Mechanistic action was mediated through activation of AMPK signaling pathway
• Nrf2 signaling pathway activation was also implicated in the attenuation of oxidative stress
• These effects were demonstrated through mice experiments examining the gut-liver/pancreas axis

FUC2 administration significantly increased the abundance of beneficial gut bacteria including Bacteroides, Faecalibaculum, and Bifidobacterium.

• FUC2 caused structural remodeling of the gut microbiota
• Beneficial bacteria with increased abundance included Bacteroides, Faecalibaculum, and Bifidobacterium
• Changes in microbiota composition consequently altered levels of microbial-derived metabolites
• Altered metabolites included short-chain fatty acids, bile acids, and amino acids

The metabolic benefits of FUC2 were mediated through the bile acid-FXR-FGF15 signaling axis.

• FUC2 modulated the gut-liver/pancreas axis through microbiota-dependent mechanisms
• The bile acid-FXR-FGF15 axis was identified as a key mediator of the metabolic benefits
• These findings were further validated by a Bacteroides supplementation experiment
• Multiomics analysis provided insights into the microbiota-gut-liver/pancreas axis modulation

A Bacteroides supplementation experiment validated the microbiota-dependent mechanisms underlying FUC2's metabolic benefits.

• Bacteroides was identified as one of the key beneficial bacteria increased by FUC2 administration
• A separate Bacteroides supplementation experiment was conducted to validate the mechanistic findings
• The validation experiment confirmed that metabolic benefits were mediated through microbiota-dependent mechanisms
• Results suggest FUC2 may serve as a potential prebiotic agent for ameliorating metabolic disorders