FFAR2 and type 2 diabetes mellitus: In addition, two receptors for SCFAs, free fatty acid receptor 3 (GPR41) and free fatty acid receptor 2 (GPR43), have been identified to be directly implicated in T2DM development, which are expressed in enteroendocrine cells, intestinal epithelial cells, pancreatic islet cells, and other cells (Stoddart and Smith, 2008; Priyadarshini et al., 2018).