Microbial dysbiosis and damage to the integrity of the colonic barrier may induce translocation of bacterial products, such as lipopolysaccharide (LPS), into the blood, which may result in activation of Toll-like receptor 4 (TLR4) and lead to inflammatory responses, insulin resistance, and obesity [35]. This evidence concerns the gene TLR4 and obesity due to melanocortin 4 receptor deficiency.