Fiber Supplementation in Heart Failure With Preserved Ejection Fraction (HFpEF)

Inclusion Criteria: * A confirmed clinical diagnosis of stable HFpEF on maximally tolerated Heart Failure (HF) medical regimen (without changes in dosage in the prior month) * Left ventricular ejection fraction of \>50% documented in the prior 12 months * A confirmed clinical diagnosis of Type II diabetes (T2DM) with glycated hemoglobin \<10% without changes in medical regimen in the past month. Exclusion Criteria: * Current usage of pre- or probiotic usage * Antibiotic usage in the past 6 months * Current participation in another interventional clinical trial * History of potato allergy or potato starch allergy, inflammatory bowel syndrome, inflammatory bowel disease, bowel resection, Roux-en-Y gastric bypass surgery, celiac disease, Crohn's disease, or colorectal cancer * Hypoglycemic episode with blood glucose 70 milligrams per deciliter (mg/dL) within the last month * Stage IV-V chronic kidney disease * Pregnancy (self-reported) * Comorbidity limiting survival to \< 12 months