Probiotic and Synbiotic Supplements in Hemodialysis Patients

Effects of Probiotic and Synbiotic Administration on the Clinical and Biochemical Characteristics of Hemodialysis Patients: A Randomized Controlled Trial

This single-center randomized controlled trial evaluated the effects of natural probiotic and synbiotic supplementation on clinical and biochemical characteristics in adults with end-stage renal disease receiving maintenance hemodialysis at the Urology and Nephrology Center, Mansoura University, Egypt. Participants were randomized into three groups (control, probiotic, and synbiotic), with supplementation given for 6 months in the intervention groups. The study assessed changes in uremic toxins (including p-cresyl sulfate) as the primary outcome, and cardiovascular parameters, quality of life, and cognitive function as secondary outcomes. The trial aimed to determine whether modulation of gut microbiota with probiotics or synbiotics can improve outcomes in hemodialysis patients

Study Overview

• Status: Completed
• Conditions: Hemodialysis; Kidney Failure, Chronic; End Stage Renal Disease (ESRD)
• Intervention / Treatment: Dietary supplement: Natural Probiotic Supplement; Dietary supplement: Natural Synbiotic Supplement (Probiotic + Prebiotic Oat Fiber)

Detailed Description

End-stage renal disease patients receiving hemodialysis commonly have intestinal dysbiosis and accumulation of gut-derived uremic toxins. Probiotic and synbiotic supplementation may help modulate gut microbiota and reduce uremic toxin burden, but direct comparative data between probiotic and synbiotic strategies in hemodialysis patients are limited. This study was designed to assess the effects of natural probiotic and synbiotic administration on the clinical and biochemical characteristics and uremic toxin levels of hemodialysis patients at the Urology and Nephrology Center (UNC), Mansoura University, Egypt.

This was a single-center randomized controlled trial with single-blind allocation. Sixty adult patients with end-stage renal disease on regular hemodialysis were included (dropout-inflated sample size; calculated minimum sample size was 48). Participants were randomized into three groups: a control group (20 patients), a probiotic group (20 patients), and a synbiotic group (20 patients). The probiotic and synbiotic groups received supplementation for 6 months; the synbiotic intervention included natural probiotic supplementation combined with prebiotic fibers (oat). Regular hemodialysis was standardized during the trial (3 sessions/week, 4 hours/session).

The primary outcome was the effect of probiotic and synbiotic supplementation on uremic toxin levels, including p-cresyl sulfate. Secondary outcomes included cardiovascular-related parameters and comorbid clinical measures, including body mass index, anemia/ESA resistance, quality of life, and cognitive function. Assessments included laboratory testing (biochemical parameters and uremic toxins), echocardiographic evaluation by blinded cardiologists, and psychological assessment using cognitive testing (MOCA) and quality-of-life evaluation (KDQOL-36).

The completed thesis reports that both probiotic and synbiotic supplementation reduced serum p-cresyl sulfate compared with control, with a more pronounced reduction in the synbiotic group, and that some cardiovascular and quality-of-life parameters improved, while cognitive and other secondary outcomes were less pronounced. Baseline characteristics were comparable across groups, supporting successful randomization.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Dakahlia Governorate
    • Al Mansurah, Dakahlia Governorate, Egypt, 35111
      • Urology and Nephrology Center (UNC), Mansoura University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 years or older.
• End-stage renal disease patients on regular maintenance hemodialysis
• Not under active preparation for kidney transplantation within the next year (i.e., not planned for transplantation for more than one year)

Exclusion Criteria:

• Age less than 18 years
• Under active preparation for kidney transplantation
• Pregnancy
• Active malignancy
• Known structural gastrointestinal tract disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control (Standard Hemodialysis Care); Participants received standard maintenance hemodialysis care without probiotic or synbiotic supplementation for the study period.
Experimental: Probiotic Supplementation; Participants received natural probiotic supplementation in addition to standard maintenance hemodialysis care for 6 months.	Dietary supplement: Natural Probiotic Supplement; Oral natural probiotic supplementation was administered in addition to standard maintenance hemodialysis care for 6 months.
Experimental: Synbiotic Supplementation; Participants received synbiotic supplementation (natural probiotic plus prebiotic fiber [oat]) in addition to standard maintenance hemodialysis care for 6 months.	Dietary supplement: Natural Synbiotic Supplement (Probiotic + Prebiotic Oat Fiber); Oral synbiotic supplementation (natural probiotic plus prebiotic fiber [oat]) was administered in addition to standard maintenance hemodialysis care for 6 months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Serum p-Cresyl Sulfate (PCS)	Serum p-cresyl sulfate level is measured in blood. Outcome is the change from baseline to the end of the intervention.	Baseline and 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Quality of Life (Kidney Disease Quality of Life-36)	Kidney Disease Quality of Life-36 (KDQOL-36) questionnaire. Scores are reported for the KDQOL-36 subscales: Symptom/Problem List (0-100), Effects of Kidney Disease (0-100), and Burden of Kidney Disease (0-100), and the generic health components derived from the SF-12 (Physical Component Summary and Mental Component Summary). For the 0-100 KDQOL-36 subscales, higher scores indicate better quality of life (fewer symptoms/less burden). The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Cognitive Function (Montreal Cognitive Assessment)	The Montreal Cognitive Assessment (MoCA) is a screening test of global cognitive function. Total score ranges from 0 to 30, with higher scores indicating better cognitive performance. Outcome is a change in the MoCA total score from baseline to 6 months.	Baseline and 6 months
Change in Left Ventricular Ejection Fraction (LVEF)	Left ventricular ejection fraction measured by transthoracic echocardiography. The outcome is the change from baseline to 6 months. A higher percentage indicates better systolic function.	Baseline and 6 months
Change in Left Ventricular End-Diastolic Volume (LVEDV)	Left ventricular end-diastolic volume measured by transthoracic echocardiography. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Left Ventricular End-Systolic Volume (LVESV)	Left ventricular end-systolic volume measured by transthoracic echocardiography. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Left Ventricular Mass Index (LVMI)	Left ventricular mass index measured by transthoracic echocardiography. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Blood Urea Nitrogen (BUN)	Blood urea nitrogen is measured in blood. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Serum Creatinine	Serum creatinine is measured in blood. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Serum Potassium	Serum potassium is measured in blood. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Serum Phosphorus	Serum phosphorus is measured in blood. The outcome is the change from baseline to 6 months.	Baseline and 6 months
Change in Hemoglobin	Hemoglobin is measured on a complete blood count. The outcome is the change from baseline to 6 months.	Baseline and 6 months

Collaborators and Investigators

• Sponsor: Mansoura University

Publications and helpful links

General Publications

• Ramezani A, Raj DS. The gut microbiome, kidney disease, and targeted interventions. J Am Soc Nephrol. 2014 Apr;25(4):657-70. doi: 10.1681/ASN.2013080905. Epub 2013 Nov 14.
• Chen YY, Chen DQ, Chen L, Liu JR, Vaziri ND, Guo Y, Zhao YY. Microbiome-metabolome reveals the contribution of gut-kidney axis on kidney disease. J Transl Med. 2019 Jan 3;17(1):5. doi: 10.1186/s12967-018-1756-4.
• Nguyen TTU, Kim HW, Kim W. Effects of Probiotics, Prebiotics, and Synbiotics on Uremic Toxins, Inflammation, and Oxidative Stress in Hemodialysis Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Clin Med. 2021 Sep 28;10(19):4456. doi: 10.3390/jcm10194456.
• Liu S, Liu H, Chen L, Liang SS, Shi K, Meng W, Xue J, He Q, Jiang H. Effect of probiotics on the intestinal microbiota of hemodialysis patients: a randomized trial. Eur J Nutr. 2020 Dec;59(8):3755-3766. doi: 10.1007/s00394-020-02207-2. Epub 2020 Feb 28.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2025
• Primary Completion (Actual): September 30, 2025
• Study Completion (Actual): October 5, 2025

Study Registration Dates

• First Submitted: March 28, 2026
• First Submitted That Met QC Criteria: April 11, 2026
• First Posted (Actual): April 15, 2026

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 11, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Quality of life; Randomized controlled trial; End stage renal disease; Cognitive function; Gut microbiota; Probiotic; Hemodialysis; Synbiotic; Uremic toxins; p-Cresyl sulfate
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Chronic Disease; Disease Attributes; Renal Insufficiency; Renal Insufficiency, Chronic; Pathological Conditions, Signs and Symptoms; Kidney Failure, Chronic; Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Probiotics
• Other Study ID Numbers: MS.23.02.2301

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because the dataset contains sensitive clinical information collected for a single-center academic thesis, and consent and local ethics approval did not include public IPD sharing. Aggregate results will be reported in the thesis and related publications.

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