CNR1 and obesity due to melanocortin 4 receptor deficiency: Mehrpouya-Bahrami et al. (2017) investigated the effect of treating mice with a cannabinoid receptor 1 (CB1) antagonist (SR141716A, Rimonabant) on diet-induced obesity and demonstrated that CB1 blockade drastically increased the relative abundance of Akkermansia muciniphila while reducing Lachnospiraceae and Erysipelotrichaceae in the gut confirming the eCB system-mediated changes in microbiota composition.