FFAR2 and diabetes mellitus: GPR43, primarily expressed in enterocytes, butyric acid stimulates the release of peptide YY from L cells through the activation of GPR43, which in turn inhibits gastrointestinal motility and increases the release of glucagon-like peptide-1 from enteroendocrine L cells, thereby regulating intestinal function and glucose metabolism and mediating diseases such as diabetes mellitus (Brown et al., 2003).