Effects of Bombyx batryticatus extract on hyperglycemia and gut microbiota in diabetic mice induced by streptozotocin and high-fat diet

• BBE improves hyperglycemia and hyperlipidemia in diabetic mice. • BBE induces distinct clustering of gut microbiota beta-diversity. • BBE increases the abundance of Bacteroidetes and reduces Firmicutes. • BBE decrease the abundance of Escherichia and Lactobacillus. • BBE specifically regulates Bacteroides vulgatus. Bombyx batryticatus , commonly known as the stiff silkworm, has various health benefits, including anti-inflammatory, neuroprotective, and anti-diabetic effects. This study is the first to investigate the effects of Bombyx batryticatus extract (BBE) on the gut microbiome community in streptozotocin (STZ)/high-fat diet (HFD)-induced diabetic mice. Diabetic mice were treated with BBE or metformin (MT, as a positive control) for seven weeks. The results showed that both BBE and MT significantly improved glucose tolerance and fasting glucose levels in diabetic mice. Pancreatic insulin content and islet size were increased in both treatment groups compared to the diabetic model (DM) group. Additionally, BBE or MT treatment significantly suppressed hyperlipidemia and hepatic steatosis. Furthermore, gut microbiota analysis showed that BBE treatment reversed the STZ/HFD-induced increase in Firmicutes and decrease in Bacteroidetes, resulting in a normalized Firmicutes/Bacteroidetes ratio. Notably, levels of Bacteroides vulgatus were significantly increased in the BBE-treated group. Additionally, MT treatment increased the abundance of Lactobacillus gasseri and Akkermansia muciniphila in the gut microbiota. BBE demonstrates potential antidiabetic effects by improving glucose metabolism and modulating the gut microbial community in STZ/HFD-induced diabetic mice. These findings suggest that BBE may be a promising natural therapy for managing diabetes and its associated gut microbiota dysbiosis.