Short-chain fatty acid receptors and gut microbiota as therapeutic targets in metabolic, immune, and neurological diseases.

Dysbiosis is associated with various diseases. The composition and diversity of gut microbiota affect host physiology through the production of bioactive metabolites. Short-chain fatty acids are the main metabolites produced by microbial fermentation of dietary fiber. They play a crucial role in maintaining metabolic, nervous, and immune system. Short-chain fatty acids not only serve as an energy source for the host but also act as for G-protein-coupled receptor signaling molecules and histone deacetylase inhibitors. In particular, the discovery and deorphanization of free fatty acid receptors 2 and 3 (GPR43/41) have shed light on the molecular mechanisms underlying the regulation of physiological processes by short-chain fatty acids. The short-chain fatty acid receptors sense the nutrient status and transduce signals to maintain cellular homeostasis. Dysbiosis affects short-chain fatty acid production and impairs the signaling, leading to cellular dysfunction. We review the current understanding of short-chain fatty acid-mediated regulation of physiological processes and discuss the molecular pharmacology of short-chain fatty acid and the receptor. We also discuss recent advances in the use of prebiotics and probiotics in the treatment of disease.