Gracilaria extract reduce hyperglycemia by modulating gut microbial and short chain fatty acids

High blood sugar is the main feature of diabetes. In order to effectively regulate blood glucose levels, in this study, we used Gracilaria as raw material and found that 70% ethanol extract of Gracilaria (GE) and complex protease hydrolysate of Gracilaria (GH) were beneficial for decreasing fasting blood glucose, improving insulin resistance, enhancing the function of islet β-cells, and regulating the abnormal increase of TC, TG, LDL-c caused by hyperglycemia in diabetic mice. Moreover, 70% ethanol extract of Gracilaria (GE) and complex protease hydrolysate of Gracilaria (GH) affected the gut microbiota structure of diabetic mice, decreased the Firmicutes/Bacteroidetes ratio, increased the abundance of Lactobacillus and Collinsella etc. and reduced the abundance of Helicobacter and Oscillibacter etc. In addition, the content of acetic acid and butyric acid in metabolites of short-chain fatty acids had increased, which had the effect of regulating blood glucose level. The results have showed that 70% ethanol extract of Gracilaria (GE) and complex protease hydrolysate of Gracilaria (GH) are potential marine foods for maintaining blood sugar health.