FFAR2 and obesity due to melanocortin 4 receptor deficiency: It has been demonstrated that SCFAs, as specific ligands for two GPCRs, GPR43/FFA2 and GPR41/FFA3, influence host health at the cellular, tissue, and organ levels through mechanisms related to intestinal barrier function, glucose homeostasis, immunomodulation, and obesity.116,117 Over the past decades, studies have found that SCFAs directly modulate insulin secretion and tissue sensitivity, reduce inflammatory responses, and improve islet cell function by affecting the immune system.