Regarding the research keywords, “innate immunity,” “toll-like receptors,” “T cells,” “regulatory T cells,” “tumor necrosis factor-alpha,” “intestinal barrier,” “intestinal permeability,” “metabolic endotoxemia,” “intestinal dysbiosis,” “probiotics,” and “bile acids” could be divided into 3 major categories: immunity, intestinal barriers, and gut microbiota, which are directly related to the intestinal immune system and involved in the pathogenesis of obesity. Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.