Role of intestinal SCFAs homeostasis in the hepatoprotective effect of Clostridium butyricum in T2DM

Probiotic supplementation was a novel therapeutic approach for treating metabolic related diseases via "gut-liver" axis. However, the effect of Clostridium butyricum (CB) supplementation on type 2 diabetes mellitus (T2DM)-associated steatohepatitis was unknown. This study revealed that CB alleviated liver damage and hepatitis in 18 weeks-old db/db mice. Targeted metabolomics analysis showed that the dysregulated short chain fatty acids (SCFAs) metabolism homeostasis was regained by CB in the colon content of db/db mice, especially butyric acid. Treatment with sodium butyrate (NaB) significantly attenuated steatosis, inflammation, and fibrosis of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-treated HepG2 cells. In-depth mechanism research suggested that the hepatoprotective effects of CB on T2DM was associated with the suppression of IκB-α/β-arrestin2/NF-κB signaling pathway via intestinal butyrate-medicated hepatic Takeda G-protein-coupled receptor 5 (TGR5). Overall, our results demonstrated a potential novel mechanism for CB as effective nutritional intervention for T2DM-related steatohepatitis via "gut-liver" axis.