High-Fiber Diet and Acetate Supplementation Change the Gut Microbiota and Prevent the Development of Hypertension and Heart Failure in Hypertensive Mice

TLDR

Dietary fiber intake is linked to lower hypertension risk, though the underlying mechanisms remain unclear, and may involve acetate production by the gut microbiota. The study aimed to assess whether a high‑fiber diet and acetate supplementation alter the gut microbiota and prevent cardiovascular disease in hypertensive mice. The authors compared gut microbiota composition, blood pressure, cardiac and renal structure, and transcriptomes among sham and mineralocorticoid‑treated mice fed control, high‑fiber, or acetate diets. High‑fiber diet and acetate supplementation reshaped the gut microbiota, lowered blood pressure, reduced cardiac and renal fibrosis, and altered cardiac and renal gene expression, including downregulation of Egr1 and the renin‑angiotensin system, thereby protecting against hypertension‑induced cardiovascular disease.

Abstract

Dietary intake of fruit and vegetables is associated with lower incidence of hypertension, but the mechanisms involved have not been elucidated. Here, we evaluated the effect of a high-fiber diet and supplementation with the short-chain fatty acid acetate on the gut microbiota and the prevention of cardiovascular disease.Gut microbiome, cardiorenal structure/function, and blood pressure were examined in sham and mineralocorticoid excess-treated mice with a control diet, high-fiber diet, or acetate supplementation. We also determined the renal and cardiac transcriptome of mice treated with the different diets.We found that high consumption of fiber modified the gut microbiota populations and increased the abundance of acetate-producing bacteria independently of mineralocorticoid excess. Both fiber and acetate decreased gut dysbiosis, measured by the ratio of Firmicutes to Bacteroidetes, and increased the prevalence of Bacteroides acidifaciens. Compared with mineralocorticoid-excess mice fed a control diet, both high-fiber diet and acetate supplementation significantly reduced systolic and diastolic blood pressures, cardiac fibrosis, and left ventricular hypertrophy. Acetate had similar effects and markedly reduced renal fibrosis. Transcriptome analyses showed that the protective effects of high fiber and acetate were accompanied by the downregulation of cardiac and renal Egr1, a master cardiovascular regulator involved in cardiac hypertrophy, cardiorenal fibrosis, and inflammation. We also observed the upregulation of a network of genes involved in circadian rhythm in both tissues and downregulation of the renin-angiotensin system in the kidney and mitogen-activated protein kinase signaling in the heart.A diet high in fiber led to changes in the gut microbiota that played a protective role in the development of cardiovascular disease. The favorable effects of fiber may be explained by the generation and distribution of one of the main metabolites of the gut microbiota, the short-chain fatty acid acetate. Acetate effected several molecular changes associated with improved cardiovascular health and function.