 Production of short chain fatty acids SCFA is the main by-product of NDC colonic fermentation Pawlak et al. 2004. Of them, colonic propionate was found to play a critical role directly in the colon and systematically after its absorption into the circulation Wong et al. 2006. Free Fatty Acid Receptor 2 previously known as orphan G-coupled Protein Receptor 43 has been discovered to has high affinity to propionate Brown et al. 2003. It is expressed on the distal ileum and colon L-enteroendocrine cells Karaki et al. 2008, adipocytes and certain monocytes lineage Hong et al. 2005. 