The human microbiome, comprising 100 trillion bacteria, is vital for health and regulates metabolism, immunity, and neurological signaling; dysbiosis can lead to various diseases. The gut microbiota ferments insoluble dietary fiber and polysaccharides to produce short-chain fatty acids (SCFAs), which are essential for intestinal homeostasis and energy metabolism as well as controlling immune cell development and anti-inflammatory properties. Gut microbes also produce secondary bile acids, which act as ligands for bile acid receptors. Furthermore, the gut microbiota also produces lipids, which are associated with metabolic disorders. In addition, it is essential for cardiovascular health and preventing metabolic syndrome, cardiovascular diseases, and cancer. Moreover, the gut microbiota plays a role in red meat metabolism. The gut microbiome also influences metabolic diseases, including bile acid bioactivity and circadian misalignment. Finally, the microbiome is crucial for metabolism regulation and therapeutic interventions, with current treatments mainly involving fecal microbiota transplantation while advanced techniques like probiotics and postbiotics are being explored.