Graduate Student Literature Review: Screening, degradation mechanisms, and applications in dairy products of cholesterol-lowering lactic acid bacteria—A review

Hypercholesterolemia, a key culprit in cardiovascular diseases, poses challenges due to the limitations of current therapies, including adverse effects and poor long-term adherence. Lactic acid bacteria (LAB), lauded for their safety, versatile mechanisms, and broad applicability across food, pharmaceutical, and livestock sectors, emerge as a promising natural alternative for cholesterol management. This study provides a comprehensive overview of the role of cholesterol and the risk of high intake, screening of cholesterol-lowering LAB and their in vitro and in vivo degradation mechanisms, and further summarizes the potential of their application in dairy products. The results show that LAB significantly modulate cholesterol levels in the gut through mechanisms such as cholesterol absorption and adsorption, coprecipitation with bile salts, and the production of metabolites such as short-chain fatty acids and exopolysaccharides. These processes help reduce serum cholesterol by influencing the host's lipid metabolism. Additionally, the synergistic effects of LAB with plant-based ingredients and physical treatments (such as ultrasound, pulsed electric fields, and UV radiation) further enhance their cholesterol-lowering capabilities. However, LAB may experience reduced activity due to exposure to high temperatures, acidic environments, and digestive enzymes during food processing. Moreover, challenges persist concerning strain stability, clinical validation, and personalized intestinal microbiota interactions. Future research should focus on optimizing and screening LAB strains, developing stable and bioavailable products, and conducting clinical trials to validate cholesterol-lowering effects in diverse populations. By integrating cross-disciplinary insights, this review aims to guide future research and support the pivotal role of LAB in cholesterol management and the promotion of cardiovascular health.