Bacillus amyloliquefaciens Fmb50 Alleviates Hyperglycemia by Reshaping Gut Structures and Mitigating Metabolic Disorders in Type 2 Diabetic Mice

Type 2 diabetes mellitus (T2DM) is often accompanied by a glucose metabolism disorder and intestinal microbial dysbiosis. In this study, underlying hypoglycemic mechanisms of surfactin-producing strain Bacillus amyloliquefaciens Fmb50 (Fmb50) and its spores were investigated. Fmb50 and its spore alleviated hyperglycemia in T2DM mice by reducing fasting blood glucose and improving oral glucose tolerance. Fmb50 and its spore decreased serum (glucose, GSP) and liver indicators (TG, TC), inhibited hepatic lipid accumulation, and reversed liver, pancreas, epididymal adipose tissue, and intestinal barrier injuries. According to 16S rRNA analysis and SCFAs detection, Fmb50 and its spore activated the hepatic AMPK pathway and reduced protein levels of G6Pase and PEPCK probably through regulating intestinal microbiota, inhibiting inflammatory response, and repairing the intestinal barrier. Collectively, Fmb50 and its spore migrated insulin resistance via gut-SCFAs-liver axis. All of these results have revealed that Fmb50 and its spore possess the ability to intestinal colonization and further alleviate T2DM in mice. These findings suggest that Fmb50 may be a promising candidate for functional food development in individuals with hyperglycemia and insulin resistance.