INS and obesity due to melanocortin 4 receptor deficiency: While Lactobacilli relative abundance in the gut microbiota in obesity and after weight loss is controversial, it has been described that specific Lactobacillus strains (e.g. L. rhamnosus, L. gasseri, L. plantarum or L. paracasei) relates with a reduction of obesity-associated metabolic disorders and even an improvement on insulin sensitivity.