L. hilgardii, as a probiotic, also improved blood glucose and blood lipid metabolism and pancreas function by increasing the expression of gut-secreted hormones with anti-obesity and anti-diabetic actions, such as the glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) [54]. The gene discussed is PYY; the disease is obesity due to melanocortin 4 receptor deficiency.