Interplay between gut microbiota and tryptophan metabolism in type 2 diabetic mice treated with metformin

This study provides valuable insights into the interrelationship between metformin administration, changes in the tryptophan (TRP) metabolome, and gut microbiota in type 2 diabetes mellitus (T2DM) mice. Indole-3-lactic acid (ILA)/indole-3-propionic acid (IPA) emerges as a potential biomarker for the development of T2DM and prediction of therapeutic response. While the indole metabolic pathway has long been associated exclusively with the gut microbiome, recent research has demonstrated the ability of host interleukin-4-induced-1 to metabolize TRP. The detection of indole derivatives in the serum of germ-free mice suggests the existence of inherent endogenous indole metabolic pathways. These findings deepen our understanding of metformin's efficacy in correcting TRP metabolic disorders and provide valuable directions for further investigation. Moreover, this knowledge may pave the way for the development of targeted treatment strategies for T2DM, focusing on the gut microbiome and restoration of associated TRP metabolism.