Effect of fruits granola (Frugra®) consumption on blood pressure reduction and intestinal microbiome in patients undergoing hemodialysis

Cardiovascular diseases (CVDs) are a major cause of death in patients undergoing hemodialysis (HD). Blood pressure (BP) and uremic toxins are well-known risk factors for CVDs, which are influenced by diet. Dietary fiber supplementation in patients undergoing HD may reduce the risk of CVDs by improving lipid profiles and inflammatory status and lowering the levels of the uremic toxin indoxyl sulfate (IS). In this study, we investigated the relationship between the intestinal microbiota and risk factors for CVDs, such as BP and serum IS, in patients undergoing HD who consumed fruits granola (FGR). The study participants were selected from patients undergoing HD at the Izu Nagaoka Daiichi Clinic and consumed FGR for 2 months. Body composition and blood samples were tested at months 0, 1, 2 and fecal samples were collected at months 0 and 2 for intestinal microbiota analysis. FGR consumption decreased systolic and diastolic BP, estimated salt intake, and serum IS levels and improved the stool characteristics according to the Bristol Stool Form Scale (N = 24). Gut microbiota analysis showed an increase in the alpha diversity and abundance of Blautia and Neglecta. The abundance of lactic acid- and ethanol-producing bacteria also significantly increased, whereas the abundance of indole-producing bacteria significantly decreased. FGR consumption could be a useful tool for salt reduction, fiber supplementation, and improvement of the intestinal environment, thus contributing to improvement of BP and the reduction of other risk factors for CVDs in patients undergoing HD.