INS and obesity due to melanocortin 4 receptor deficiency: Therefore, to verify this hypothesis, we investigated the effects of MOP on body weight, fat accumulation, blood lipid levels, insulin resistance, chronic inflammation, and gut microbiota in a HFD-induced obese mice, and further investigated the correlation of gut bacteria with obesity-related parameters including host obesity phenotype, blood lipids, glucose homeostasis, and pro-inflammatory cytokines.