Prebiotics play a role in animal models of obesity and diabetes by promoting the proliferation of beneficial bacteria such as Lactobacillus and Bifidobacterium, improving enteroendocrine cell activity, enhancing the postprandial secretion of hormones that promote satiety, improving glucose and lipid metabolism, increasing leptin sensitivity, and improving intestinal barrier permeability [123,124,125]. This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.