Figure 2.

Schematic of potential mechanisms linking the gut microbial community with glucose metabolism. Potential mechanisms include 1) systemic absorption of LPS, either through “leaky” tight junctions or via chylomicron uptake, with subsequent inflammation; 2) bacterial production of SCFAs with signaling effects to stimulate secretion of gut hormones GLP-1 and GLP-2 and PYY as well as nutrient effects; 3) bacterial synthesis and absorption of branched chain amino acids (AAs) that may result in insulin resistance; 4) bacterial metabolism of bile acids with local and organ-specific signaling effects, including stimulation of fibroblast growth factor-19 (FGF-19) and GLP-1. FGF-19 has metabolic effects on the FXR in the pancreatic β-cell and in the liver.