GCG and obesity due to melanocortin 4 receptor deficiency: Demonstrating the important roles of GLP-1 analogs and GLP-1 receptor agonists in the modern therapy of type 2 diabetes and obesity, and given their complex pathophysiology, including potential changes in the gut microbiome environment, we undertook to examine the current state of knowledge on the effects of the cited drugs on the state of the gut microbiome.