FFAR2 and obesity due to melanocortin 4 receptor deficiency: Butyrate can regulate energy expenditure and induce mitochondrial function through the function of its cellular receptors, free fatty acid receptor 2 (FFAR2) or free fatty acid receptor 3 (FFAR3) [58], thus it can be involved in inflammation, glucagon-like peptide-1 (GLP-1) secretion and body energy regulation [59,60,61,62], which in turn play a role in the prevention of obesity, atherosclerosis, and other cardiovascular diseases.