Low-grade inflammation in obesity is a consequence of gut microbiota alterations due to the presence of lipopolysaccharides (LPSs), which activate nuclear factor-κB (NF-κB) and interfere with the secretion of pro-inflammatory cytokines such as type I interferon (IFN)-γ, TNF-α, IL-6, IL-1β, IL-8, and MCP-1 [4,5]. The gene discussed is IL6; the disease is obesity due to melanocortin 4 receptor deficiency.