The chapter discusses the complex relationship between satiety, the gut microbiome, and the brain. It highlights how hormones like GLP-1, CCK, and PYY, produced by enteroendocrine cells in the gastrointestinal tract, play crucial roles in signaling satiety to the brain via the vagus nerve. GLP-1, in particular, has been shown to be a promising target for weight loss treatments. The gut microbiome also influences satiety through its impact on the production of short-chain fatty acids (SCFAs) and other microbial products that affect hormone release. Additionally, the chapter explores the role of neurotransmitters such as GABA and serotonin in regulating energy balance and satiety. The interplay between the gut microbiome, hormones, and neurotransmitters is essential for maintaining homeostasis and controlling food intake. The chapter concludes by emphasizing the potential of ongoing research in this area to develop new treatments for metabolic disorders.The chapter discusses the complex relationship between satiety, the gut microbiome, and the brain. It highlights how hormones like GLP-1, CCK, and PYY, produced by enteroendocrine cells in the gastrointestinal tract, play crucial roles in signaling satiety to the brain via the vagus nerve. GLP-1, in particular, has been shown to be a promising target for weight loss treatments. The gut microbiome also influences satiety through its impact on the production of short-chain fatty acids (SCFAs) and other microbial products that affect hormone release. Additionally, the chapter explores the role of neurotransmitters such as GABA and serotonin in regulating energy balance and satiety. The interplay between the gut microbiome, hormones, and neurotransmitters is essential for maintaining homeostasis and controlling food intake. The chapter concludes by emphasizing the potential of ongoing research in this area to develop new treatments for metabolic disorders.