Alginate oligosaccharides and glycolipid metabolism: Correlation with gut microbiota modulation in mice and clinical feces

Glycolipid metabolism disorders, such as diabetes, fatty liver, hyperlipidemia, pose significant threats on human health. Alginate oligosaccharides (AOS), derived from the degradation of alginate, exhibit numerous biological activities and are readily absorbed. This study investigated the potential beneficial effects of AOS in ameliorating glycolipid metabolism disorders through the modulation of gut microbiota. The findings demonstrated that AOS effectively improved glycolipid metabolism disorders by reducing blood glucose, cholesterol, and triglycerides levels, as well as regulating the expression of key metabolic genes, including PEPCK, G6Pase, HMGCR, CYP7A1, LDLR, SMYD3, SREBP-2, in a type 2 diabetes (T2DM) mouse model induced by streptozotocin combined a high-fat-diet ( in vivo ) and in oleic acid-induced hepatocyte steatosis ( in vitro ). Additionally, AOS alleviated pathological damage to the liver and the kidney, modulated the composition of gut microbiota, and enhanced the production of short-chain fatty acids (SCFAs) in T2DM mice. Furthermore, AOS was efficiently degraded and utilized in the in vitro fermentation by the gut microbiota from nonalcoholic fatty liver disease (NAFLD) patients, promoting the production of SCFAs and significantly enhancing the proliferation of gut benefical bacteria, such as lactobacillus . To the best of our knowledge, this study was the first to elucidate the mechanism by which AOS improves glycolipid metabolism disorder through the regulation of gut microbiota, both in animal models and in clinical patient fecal samples.