INS and obesity due to melanocortin 4 receptor deficiency: Several studies in animals and in vitro models have demonstrated the effect of probiotics (of the species Lactobacillus) on increased incretin secretion (GLP-1) and consequently glucose control, as well as reducing signs of obesity and/or type 2 diabetes, i.e., postprandial glucose and insulin resistance [100,101,147,155,213,214].