A diet rich in non-digestible polysaccharides (so-called fiber) is associated with a lower mortality from cardiovascular disease. Dietary fiber is fermented by gut bacteria to short-chain fatty acids (SCFA). SCFA, especially propionate, were previously shown to act anti-inflammatory via their influence on regulatory T cells (Treg). Inflammation plays a crucial role in hypertension and associated organ damage and Treg were shown to improve hypertensive cardiac damage. DZHK scientists from Berlin and Greifswald together with colleagues from the Heinrich-Heine University of Düsseldorf addressed the question whether propionate administration could improve hypertensive organ damage.
Propionate administration in the drinking water could improve cardiac hypertrophy, fibrosis and susceptibility to arrhythmias in a hypertensive mouse model. Propionate improved systemic inflammation and local cardiac infiltration with immune cells. Treg depletion blocked the protective effects of propionate. In a second hypertensive mouse model - prone to develop atherosclerosis - propionate also improved cardiac hypertrophy, fibrosis and systemic inflammation as well as aortic atherosclerosis and local inflammation of the aorta. Propionate treatment reduced blood pressure in the late phase of the experiment in both models. Blood pressure effects were Treg-independent.
The results of the study could explain the above-mentioned association between a fiber-rich diet and prevention of cardiovascular disease. Propionate administration or therapies targeting the gut microbiome-dependent production of propionate and other SCFA (e.g. lifestyle, diet) could be promising targets in hypertensive patients.
This study was funded through a DZHK partner site project. Hendrik Bartolomaeus received a DZHK doctoral scholarship to work on this project.