INS and obesity due to melanocortin 4 receptor deficiency: Chain fatty-acids, bile-acids, butyrate, epithelial-mesenchymal transition, tumor microenvironment, carcinogenesis, salmonella typhimurium a1-r, t-cells, probiotics, pathway, oxidative stress, obesity, nf-kappa-b, metabolites, kras, macrophages, insulin-resistance, inflammatory-bowel-disease, high-fat diet, fusobacterium-nucleatum, diversity, dysbiosis, commensal bacteria, toll-like receptors, antibiotics