Atherosclerotic cardiovascular disease (ACVD), an inflammatory disease of the coronary arteries associated with atheroma formation, remains a major global cause of disability and mortality. In 2021 alone, over 20 million individuals succumbed to cardiovascular disease (CVD), and was the leading cause of death worldwide.
Commonly acknowledged lifestyle factors such as smoking, physical activity, diet, and weight significantly contribute to arterial health. However, a recent groundbreaking study led by BGI-Research has shed light on a potential new indicator, and perhaps even a treatment, for assessing the risk of ACVD - a fascinating connection within the gut microbiota of healthy individuals.
A consortium of three-bacteria isolated from human feces inhibits formation of atherosclerotic deposits and lowers lipid levels in a mouse model is published in iScience.
Drawing on the existing comprehensive research focused on the gut microbiome of individuals with ACVD, scientists discovered a significant reduction in three key bacterial strains - Bacteroides cellulosilyticus, Faecalibacterium prausnitzii, and Roseburia intestinalis - within the overall gut microbiota composition of ACVD patients. Interestingly, Faecalibacterium prausnitzii also exhibited a notable decline in composition percentage of the gut microbiome among obese individuals.
Moreover, analysis of gut microbiota data obtained from a large cohort study of healthy individuals unveiled the crucial role of these three bacteria as core components of a healthy microbiota, demonstrating a connection with cardiovascular indicators, such as blood lipids, that goes in the opposite direction.
These findings suggest that these specific bacterial strains possess probiotic potential in the regulation of cardiovascular disease.
To validate this hypothesis, the researchers cultivated these three bacterial strains and evaluated their efficacy in regulating cardiovascular function using a mouse model of atherosclerosis. The results consistently demonstrated that the administration of these bacterial strains, either individually or in combination, improved heart function, lowered lipid (fat) levels, and impeded the progression of atherosclerosis.
Further exploration into the underlying mechanism revealed that the microbiota, by influencing the production of secondary bile acids, facilitated a reduction in triglyceride and low-density lipoprotein (LDL) levels within the mice.
Triglycerides represent the predominant type of lipids circulating in the human body, providing energy for cellular processes. Lipoproteins are particles made of protein and lipids, which carry cholesterol through human bloodstream to cells. Among lipoproteins, LDL is considered the "bad" type, in contrast to HDL (high-density lipoprotein). Elevated triglyceride and LDL levels heighten the risk of initial and recurrent ACVD events.
The mechanism of three bacterial strains regulating cardiovascular functions in the mouse model.
The results illustrated how these three bacterial strains reshaped the gut microbiota in mice with cardiovascular conditions, promoting the conversion of primary bile acids into secondary bile acids. The production of secondary bile acids activated a unique receptor known as farnesoid X in the liver, subsequently inhibiting lipid synthesis and fostering lipid degradation.
Dr. Jie Zhuye, a researcher from BGI-Research and the study's first author, emphasized the untapped potential of the gut microbiota in healthy individuals to regulate chronic diseases, including cardiovascular diseases. Dr. Jie stated, "The study's findings offer a novel intervention approach for managing cardiovascular diseases, underscoring the importance of identifying gut microbiota markers in large populations and cultivating strains from healthy individuals."
The project underwent ethical review, adhered to regulations, and followed privacy protocols.
Read the article:
https://www.sciencedirect.com/science/article/pii/S2589004223010374