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

Kidney transplantation is the best therapeutic option for patients with advanced CKD and ESKD. It significantly improves quality of life and survival. However, kidney transplant recipients remain facing higher mortality compared to the general population. Similar to the non-transplant population, cardiovascular disease (CVD) is the most common cause of mortality in kidney transplant recipients and hypertension is one of the most common risk factors for CVD. While a plant-based diet is associated with improved blood pressure control, there is a lack of evidence of the benefit of a plant-based diet in kidney transplant recipients. Recently, the gut microbiota has emerged, and the impact appears to be bidirectional. Gut microbiota participates in various effects in the human body such as the synthesis of vitamins, production of short-chain fatty acids, degradation of plant polysaccharides, and immune system development. In CKD, there is alteration in gut microbiota most notably as decrease in the Lactobacillaceae and Prevotellaceae families. After successful kidney transplantation, gut microbial dysbiosis has also been observed and typically characterized by a decrease in microbial diversity and an increase in the relative prevalence of Proteobacteria in comparison to individuals with normal health. Evidence has demonstrated the association of gut microbiota on kidney transplant outcomes such as hypertension, allograft rejection, immunosuppressant metabolism, and post-transplant infection. Therefore, dietary intervention is one of the non-pharmacologic options that can modify and change gut microbiota.

Several types of plant-based diets are associated with beneficial effects on kidney transplant outcomes. For instance, Mediterranean diet is associated with a lower incidence of metabolic syndrome. Dietary Approaches to Stop Hypertension (DASH) diet is associated with a lower risk of kidney allograft function decline and all-cause mortality. Studies have shown the interaction among plant-based dietary consumption, gut microbiota composition, and blood pressure. Although these dietary patterns-related clinical outcomes are associated with improved gut microbiota in kidney transplant recipients, there is a lack of data about the association between consuming plant-based diet, change in gut microbiota, and blood pressure control in kidney transplant recipients. Therefore, the investigators hypothesize that plant-based diet consumption improves blood pressure control and gut microbiota; while, does not decrease the quality of life in kidney transplant recipients

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