The development of atherosclerosis is significantly influenced by the interplay between lipid and inflammatory factors. Endotoxemia, defined as the presence of endotoxins, particularly lipopolysaccharides (LPS) derived from Gram-negative bacteria, in the bloodstream, is closely associated with low-grade inflammation. This chronic, systemic inflammatory response does not reach the severity of acute inflammation but can contribute to the development of atherosclerosis and cardiovascular disease (CVD). Lipopolysaccharide-binding protein (LBP) is a soluble acute-phase protein that binds to bacterial LPS. Elevated levels of LBP have been linked to increased low-grade inflammation, which further exacerbates chronic inflammation and metabolic dysregulation. Dietary fiber, such as oat bran, may have a role in mitigating the effects of endotoxemia and its associated inflammation. Furthermore, dietary fiber could play a role in improving plasma lipid profiles. The present study will investigate the effect of oat bran supplementation on cardiometabolic risk markers, LBP concentrations, selected fecal bacteria, and short-chain fatty acids receptors gene expression in peripheral blood mononuclear cells in patients with coronary artery disease.