Gut microbiota-derived metabolites play a crucial role in regulating host homeostasis. These metabolites, including short-chain fatty acids (SCFAs), bile acids, amino acid derivatives, and membrane lipids, influence various physiological processes such as metabolism, mucosal immunity, and gut barrier function. They interact with host cells through specific receptors, particularly G-protein-coupled receptors (GPRs), to modulate immune responses and maintain balance. SCFAs, produced by bacteria like Bacteroidetes and Firmicutes, are essential for gut health, affecting immune cell function and barrier integrity. Bile acids, modified by gut microbiota, influence liver function and immune responses. Amino acid-derived metabolites, such as those from tryptophan, impact immune regulation and inflammation. Lipid metabolites, including those from bacterial membranes, contribute to immune modulation and barrier function. The gut microbiota also influences the gut-liver, gut-pancreas, gut-lung, and gut-bone marrow axes, affecting systemic health. Therapeutic strategies targeting these metabolites, such as probiotics, prebiotics, and dietary interventions, show promise in treating diseases. Understanding the complex interactions between gut microbiota and host homeostasis is essential for developing effective treatments and maintaining health.Gut microbiota-derived metabolites play a crucial role in regulating host homeostasis. These metabolites, including short-chain fatty acids (SCFAs), bile acids, amino acid derivatives, and membrane lipids, influence various physiological processes such as metabolism, mucosal immunity, and gut barrier function. They interact with host cells through specific receptors, particularly G-protein-coupled receptors (GPRs), to modulate immune responses and maintain balance. SCFAs, produced by bacteria like Bacteroidetes and Firmicutes, are essential for gut health, affecting immune cell function and barrier integrity. Bile acids, modified by gut microbiota, influence liver function and immune responses. Amino acid-derived metabolites, such as those from tryptophan, impact immune regulation and inflammation. Lipid metabolites, including those from bacterial membranes, contribute to immune modulation and barrier function. The gut microbiota also influences the gut-liver, gut-pancreas, gut-lung, and gut-bone marrow axes, affecting systemic health. Therapeutic strategies targeting these metabolites, such as probiotics, prebiotics, and dietary interventions, show promise in treating diseases. Understanding the complex interactions between gut microbiota and host homeostasis is essential for developing effective treatments and maintaining health.