Dietary Fiber Supplementation Reduces Systolic Blood Pressure in High-Risk Patients with Type 2 Diabetes and Hypertension: A Secondary Analysis of a Randomized Trial

Background/Objectives: Dietary fiber supplementation has been associated with blood pressure (BP) reduction, but evidence comparing soluble (SDF) and insoluble (IDF) fiber types in high-risk populations is limited. This study aimed to compare the effects of SDF and IDF supplementation on BP and to explore correlations between changes in BP and alterations in gut microbiota composition and serum biomarkers in adults with type 2 diabetes (T2D) and hypertension.

Methods

This secondary analysis was based on a 12-week, randomized, double-blind, parallel-group clinical trial. Thirty-five adults with T2D and hypertension were assigned to receive either 5 g/day of oat β-glucan (SDF, n = 19) or microcrystalline cellulose (IDF, n = 16). BP, gut microbiota composition (quantitative polymerase chain reaction; qPCR), and inflammatory biomarkers were assessed at baseline and after the intervention.