In addition, we previously showed that BL21 positively affected the gut microbiota and ameliorated hepatic metabolic abnormalities in high-fat diet (HFD)-induced obese mice and streptozotocin (STZ)-induced T2DM mice and that BL21 decreased the elevated FBG and fasting serum insulin levels in T2DM mice (Wu et al. 2020b; Hao et al. 2022). Here, INS is linked to type 2 diabetes mellitus.