LEPR and obesity due to melanocortin 4 receptor deficiency: The possible mechanisms of T2DM induced by the intestinal microbiota include disorders of lipid metabolism, endotoxemia, bile acid metabolism, insulin resistance etc. In order to better understand the role of intestinal microbiota in the obesity-T2DM process and the possible mechanism, we used Zucker Diabetic Fatty (ZDF) rats with mutations in the leptin receptor gene as a research model, which can gradually produce spontaneous obesity and hyperglycemia with age.