How a Plant-Based Diet Affects Blood Pressure and Gut Health in Kidney Transplant Patient

Kidney transplant improves the quality of life (QoL) and survival of appropriate patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD). However, these patients still have higher mortality compared to the general population and cardiovascular disease (CVD) is the leading cause of mortality. Among several metabolic complications post-transplantation, hypertension is one of the common risk factors for CVD. In addition to cardiometabolic alteration post-transplant, there is often observed gut microbial dysbiosis, marked by a decrease in microbial diversity and an increase in the relative abundance of Proteobacteria compared to individuals in a healthy state. Different dietary patterns can lead to distinct gut microbiota compositions. Diets rich in plant-based foods, whole grains, fruits, and vegetables tend to promote a more diverse and beneficial gut microbiota characterized by a higher abundance of fiber-degrading bacteria. On the other hand, diets high in saturated fats, refined sugars, and processed foods have been associated with dysbiosis, characterized by a reduction in beneficial bacteria and an overgrowth of potentially harmful microbes. While there is data in the normal population suggesting that a healthy diet can alter gut microbiota composition, the impact of a plant-based diet on gut microbiota-associated hypertension in kidney transplant recipients remains understudied. To address this gap, the investigators propose a single-center, open-label, 1:1 parallel randomized controlled trial to examine the effect of consuming a plant-based diet (intervention group) for 12 weeks on the change in blood pressure, gut microbiota, and patient report outcomes compared to the habitual diet (control group) in kidney transplant recipients with stable kidney allograft function at least 3 months post-transplantation. The investigators hypothesize that the adoption of a plant-based diet decreases in blood pressure, induces significant changes in gut microbiota composition and does not change in QoL.

Inclusion Criteria: * Receive kidney transplantation at least 3 months before enrollment with stable kidney allograft function defined by ≤ 25% change in an estimated glomerular filtration rate (eGFR) from the baseline eGFR at 3-month post-transplant for 2 consecutive values closest to the date of randomization. The most recent eGFR before randomization ≥ 30 ml/min/1.73 m2. * An average SBP ≥ 120 and ≤ 160 mmHg at the time of randomization. * No change in type and dose of antihypertensive medications ≥ 1 month before randomization or no initiation of new antihypertensive medication ≥ 1 month before randomization * Anticipated to have no change in type and dose of antihypertensive medications during the 12-week study period. * Able to attend follow-up visits according to the study protocol. Exclusion Criteria: * Combined solid organ transplantation * Serum sodium \< 135 mmol/L before randomization * Serum potassium \> 5.5 mmol/L before randomization * History of acute kidney allograft rejection of the current kidney allograft