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

June 8, 2026 updated by: Mahidol University

Effect of Plant-based Diet on Blood Pressure and Gut Microbiota in Kidney Transplant Recipients

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.

Study Overview

Detailed Description

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

Study Type

Interventional

Enrollment (Actual)

102

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Bangkok, Thailand, 10400
        • Ramathibodi Hospital, 270 Rama VI Rd. Thung Phaya Thai, Ratchathewi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Control

The normal diet for the control group is defined as a standard dietary intake without specific restrictions on protein sources. The dietary guidelines are as follows:

Caloric Intake: 30-35 kcal per kilogram of body weight per day. Protein Intake: 0.8-1 g per kilogram of body weight per day, with no restrictions on the source of protein.

Sodium Intake: Participants are encouraged to follow a low-sodium diet, limiting sodium intake to less than 2 g per day, in accordance with dietary recommendations for patients with chronic kidney disease (CKD).

Experimental: Plant based diet

The plant-based diet in this study is defined as a predominantly vegetarian dietary pattern, consisting of two vegetarian meals per day and one meal that includes animal-derived protein. The diet is based on whole foods while avoiding ultra-processed foods.

Macronutrient Composition Caloric Intake: 30-35 kcal per kilogram of body weight per day Protein Intake: 0.8-1 g per kilogram of body weight per day Fat Sources Animal-derived fats are to be avoided. Plant-based oils are recommended as the primary source of dietary fats. Protein Sources Emphasis is placed on plant-based protein sources, including nuts, beans, edamame, tofu, and tempeh.

Dairy consumption is permitted, but cow's milk is discouraged. Instead, plant-based alternatives such as almond milk and soy-based milk (e.g., tofu milk) are recommended.

Egg consumption is allowed but limited to no more than one egg per day

The plant-based diet in this study is defined as a predominantly vegetarian dietary pattern, consisting of two vegetarian meals per day and one meal that includes animal-derived protein. The diet is based on whole foods while avoiding ultra-processed foods.

Macronutrient Composition Caloric Intake: 30-35 kcal per kilogram of body weight per day Protein Intake: 0.8-1 g per kilogram of body weight per day Fat Sources Animal-derived fats are to be avoided. Plant-based oils are recommended as the primary source of dietary fats. Protein Sources Emphasis is placed on plant-based protein sources, including nuts, beans, edamame, tofu, and tempeh.

Dairy consumption is permitted, but cow's milk is discouraged. Instead, plant-based alternatives such as almond milk and soy-based milk (e.g., tofu milk) are recommended.

Egg consumption is allowed but limited to no more than one egg per day

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference change of blood pressure
Time Frame: 12 weeks
The difference in mean blood pressure change at 12 weeks from the baseline between the intervention and control groups.
12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quality of life by 5EQ-5D-5L score
Time Frame: 12 weeks
Change in quality of life assessed by 5EQ-5D-5L between intervention and control groups
12 weeks
Kidney allograft function
Time Frame: 12 weeks
Change in kidney allograft function between the intervention and control groups, assessed using serum creatinine.
12 weeks
Kidney allograft function
Time Frame: 12 weeks
Change in kidney allograft function between the intervention and control groups, assessed using eGFR.
12 weeks
Gutmicrobiota
Time Frame: 12 weeks
The difference in gut microbiota composition between the two groups at 12 weeks from baseline, as determined by 16S rRNA sequencing from stool and 3 parameters including alpha diversity, beta diversity, and gut bacterial profile and composition will be evaluated.
12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Chair: Surasak Kantachuvesiri, M.D, Ph.D., Ramathibodi Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 29, 2025

Primary Completion (Actual)

November 26, 2025

Study Completion (Actual)

November 26, 2025

Study Registration Dates

First Submitted

March 6, 2025

First Submitted That Met QC Criteria

March 6, 2025

First Posted (Actual)

March 12, 2025

Study Record Updates

Last Update Posted (Actual)

June 10, 2026

Last Update Submitted That Met QC Criteria

June 8, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) from this study will not be shared. This decision is made to protect participant confidentiality and ensure compliance with institutional and ethical guidelines regarding data privacy

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe