BCAA dysmetabolism in the host and gut microbiome, a key player in the development of obesity and T2DM

Branched chain amino acids (BCAAs) are essential amino acids required by mammals. Recently, accumulating evidence has revealed the important connection between the alterations of BCAAs and their metabolites in circulation and the development and prognosis of chronic metabolic diseases, especially obesity and type 2 diabetes mellitus (T2DM). The connection strongly suggests the pivotal role of dysregulated BCAA metabolism in obesity and T2DM. More importantly, BCAA anabolic and catabolic defects in host and gut microbiome often intertwine with glucose and lipid metabolism, which synergistically promote systemic insulin resistance and obesity/T2DM progression. However, the mutual effects of BCAA with glucose/lipid metabolism in different tissues of the host and the association of BCAA with gut microbiota, are not fully understood and summarized. In the current review, we focus on the mutual effects of BCAA with glucose/lipid metabolism in the host and gut microbiota modulation of BCAA metabolism, and further discuss the metabolic regulatory effects on the development of obesity and T2DM.