Short chain fatty acids (SCFAs), including acetate, propionate, and butyrate, are produced by gut bacteria during the fermentation of dietary polysaccharides. These SCFAs play critical roles in regulating intestinal energy metabolism, maintaining gut homeostasis, and influencing immune and metabolic functions outside the gut. Recent studies have identified two main signaling mechanisms: activation of G-protein coupled receptors (GPCRs) and inhibition of histone deacetylase (HDAC). SCFAs are important regulators of inflammation and disease, with each SCFA playing a unique role in health and disease development. SCFAs are absorbed by the colon and transported to various organs, where they influence energy metabolism, immune responses, and inflammation. Acetate is primarily metabolized by the liver, while propionate and butyrate are mainly processed by colonocytes. SCFAs can act as signaling molecules, modulating gene expression and cellular functions through GPCRs and HDAC inhibition. They also influence immune cell function, including T-cell differentiation, neutrophil activity, and macrophage responses. SCFAs have been shown to regulate inflammation by modulating cytokine production and immune cell function. For example, butyrate reduces inflammation by inhibiting NF-κB activation and promoting the differentiation of regulatory T cells. Propionate has anti-inflammatory effects and can improve metabolic health. Acetate has been shown to reduce inflammation and improve liver function in non-alcoholic fatty liver disease. SCFAs also play important roles in various diseases, including obesity, diabetes, cancer, and kidney disease. Butyrate, in particular, has been shown to inhibit tumor growth and promote the differentiation of regulatory T cells. Propionate can improve metabolic health and reduce inflammation. Acetate has been shown to reduce inflammation and improve liver function. Overall, SCFAs are important mediators of gut microbiota-host interactions and play critical roles in maintaining health and preventing disease. Further research is needed to fully understand the mechanisms by which SCFAs influence health and disease, and to develop targeted therapies based on SCFA regulation.Short chain fatty acids (SCFAs), including acetate, propionate, and butyrate, are produced by gut bacteria during the fermentation of dietary polysaccharides. These SCFAs play critical roles in regulating intestinal energy metabolism, maintaining gut homeostasis, and influencing immune and metabolic functions outside the gut. Recent studies have identified two main signaling mechanisms: activation of G-protein coupled receptors (GPCRs) and inhibition of histone deacetylase (HDAC). SCFAs are important regulators of inflammation and disease, with each SCFA playing a unique role in health and disease development. SCFAs are absorbed by the colon and transported to various organs, where they influence energy metabolism, immune responses, and inflammation. Acetate is primarily metabolized by the liver, while propionate and butyrate are mainly processed by colonocytes. SCFAs can act as signaling molecules, modulating gene expression and cellular functions through GPCRs and HDAC inhibition. They also influence immune cell function, including T-cell differentiation, neutrophil activity, and macrophage responses. SCFAs have been shown to regulate inflammation by modulating cytokine production and immune cell function. For example, butyrate reduces inflammation by inhibiting NF-κB activation and promoting the differentiation of regulatory T cells. Propionate has anti-inflammatory effects and can improve metabolic health. Acetate has been shown to reduce inflammation and improve liver function in non-alcoholic fatty liver disease. SCFAs also play important roles in various diseases, including obesity, diabetes, cancer, and kidney disease. Butyrate, in particular, has been shown to inhibit tumor growth and promote the differentiation of regulatory T cells. Propionate can improve metabolic health and reduce inflammation. Acetate has been shown to reduce inflammation and improve liver function. Overall, SCFAs are important mediators of gut microbiota-host interactions and play critical roles in maintaining health and preventing disease. Further research is needed to fully understand the mechanisms by which SCFAs influence health and disease, and to develop targeted therapies based on SCFA regulation.