Namely, Akkermansia secreted protein, P9, was responsible for GLP-1 secretion through its interaction with intracellular adhesion molecule-2, an effect which was diminished by the pro-inflammatory cytokine interleukin-6 that is increased in chronic high fat feeding and obesity in mice [96,97]. Here, GLP1R is linked to obesity due to melanocortin 4 receptor deficiency.