PYY and obesity due to melanocortin 4 receptor deficiency: Interestingly, enteroendocrine L cells, that are part of the colonic epithelium and express SCFA receptor on their surface, upon the interaction with acetate and butyrate, produce glucagon-like peptide-1 (GLP-1) and fasting peptide YY (PYY) peptides (Brooks et al., 2017; Zhao et al., 2018) These peptides are thought to increase energy intake while decreasing appetite, hence these peptide are involved in the gut-brain axis and are potential therapeutic agents in treating conditions like obesity.