Pea Fibre in Hemodialysis

NCT07544797 | Not Yet Recruiting

• 1 other identifier: UKH-KIMII-001-26
• Study Type: interventional
• Target: 72
• Locations: 1 country
• Sites: 1

Brief Summary

Background and problem Chronic kidney disease (CKD) affects a large share of adults worldwide and is a growing public-health concern. People with advanced CKD can develop "uremia", a dangerous build-up of waste products in the blood that the failing kidneys cannot remove. Even when patients receive regular dialysis, many so-called "uremic toxins" remain in the body because some of these substances bind tightly to blood proteins and are poorly removed by dialysis. Over 100 uremic toxins have been identified and classified and protein-bound toxins such as Indoxylsulfate and p-Cresylsulfate are especially difficult to clear by dialysis. Some uremic toxins are linked to heart and blood-vessel disease, inflammation, and worse outcomes in dialysis patients. For example, Indoxylsulfate has been associated with higher mortality, vascular calcification, vessel stiffness and heart failure. Reducing these toxins might therefore improve quality of life and lower cardiovascular risk in people on dialysis. Purpose of the study The study will test whether adding inner, fermentable pea fiber (a natural prebiotic) to the daily diet of hemodialysis patients can lower blood levels of uremic toxins-especially Indoxylsulfate-and improve related markers of inflammation and cardiovascular risk. The investigators hypothesize that fermentable fibers change gut bacterial composition so that less toxin-forming bacterial metabolism (from amino acids like tryptophan) occurs, thereby reducing the amount of harmful metabolites that reach the blood. Type of study: Randomized, double-blind, controlled trial with two groups. Duration: 8 weeks of intervention. Intervention: Participants will receive daily baked goods (bread, rolls, muffins, scones, pizza bread) that together provide 20 g of pea fiber per day; the control group will receive identical foods without added pea fiber. The fiber mix uses commercially available inner pea-fiber products. Blood and stool sampling: Blood samples are taken before the intervention, at 4 weeks and at 8 weeks to measure Indoxylsulfate and other toxins, inflammation markers, vitamin D metabolites and cardiovascular risk markers. A subgroup will also provide stool samples to study changes in the gut microbiome. Who can join Adults aged 18-89 who have been on chronic hemodialysis for at least three months and receive dialysis two to three times per week are eligible. The study excludes people with recent serious infections, advanced liver disease, active cancer, recent blood transfusion, pregnancy, certain food intolerances or inability to consent. Each study arm will include 36 participants. Primary and secondary outcomes Primary outcome: Change in blood Indoxylsulfate concentration between the pea-fiber group and the control group. Secondary outcomes: Levels of other uremic toxins, routine kidney-related blood tests (creatinine, urea, uric acid), electrolytes, vitamin D metabolites, inflammatory markers, lipid markers, FGF23, short-chain fatty acids, sKlotho, and the effect of patient serum on cytokine production in a standard immune cell line. Stool analyses in a subgroup will examine shifts in bacterial groups and metabolic networks. How the intervention is delivered and monitored Foods are prepared in a certified bakery and coded so neither participants nor study staff know who receives pea fiber or placebo. To improve adherence, participants choose from a variety of pre-portioned baked items and are advised to spread intake across the day. Unused portions are returned and logged. Dietary recalls and symptom questionnaires are collected to monitor changes in overall diet, appetite and gastrointestinal side effects. Blood draws are timed before dialysis after the long interdialytic interval to standardize measurements. Potential impact and limitations If fermentable inner pea fibers lower Indoxylsulfate and related toxins, this would support a simple, food-based strategy to reduce toxin burden and possibly cardiovascular risk in dialysis patients. However, previous studies show mixed results depending on the type of fiber used: fermentable fibers (like amylose-rich starch or inulin) have produced beneficial changes in some trials, while non-fermentable fibers did not. Since evidence high-quality randomized trials in dialysis patients is still limited there is the need for this study.

Conditions

Hemodialysis; Kidney Failure Chronic

Keywords

prebiotics; hemodialysis; pea fibre; indoxylsulfate; kidney failure chronic; uremic toxin

Outcome Measures

Primary Outcomes (1)

• Indoxylsulfate plasma concentration

  µg/ml

  8 weeks

Secondary Outcomes (9)

• p-cresyl sulfate plasma concentration

  8 weeks

• Trimethylamin-N-oxide plasma concentration

  8 weeks

• Tumor necrosis factor alpha plasma concentration

  8 weeks

• Interleukin-6 plasma concentration

  8 weeks

• C-reactive protein plasma concentration

  8 weeks

Other Outcomes (1)

• Interleukin-6 concentration in cell culture supernatant

  8 weeks

Study Arms (2)

Pea fibre

EXPERIMENTAL

Participants receive baked goods containing a daily amount of 20g inner pea fibres

Dietary Supplement: praebiotic inner fermentable pea fibres

Control

PLACEBO COMPARATOR

Participants receive identical baked good without inner pea fibres

Dietary Supplement: Control

Interventions

praebiotic inner fermentable pea fibres DIETARY_SUPPLEMENT

prebiotic pea fibres baked into bread, rolls, muffins, scones or pizza bread in the intervention group.

Pea fibre

Control DIETARY_SUPPLEMENT

Similar baked goods without prebiotic ingredients.

Control

Eligibility Criteria

• Age: 18 Years - 89 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• male and female patients 18-89 years of age
• chronic hemodialysis treatment minimum 3 months for any kind of kidney disease
• hemodialysis sessions per week
• expected to continue regular treatment for at least 3 months
• written informed consent

You may not qualify if:

• Persons younger than 18 or older than 89 years
• Use of immunosuppressive medications, with the exception of glucocorticoids ≤ 5 mg prednisolone equivalent
• Liver cirrhosis, Child-Pugh stage C
• Active malignancy, with or without specific oncological therapy
• Planned absence (e.g., vacation) for more than 1 week during the study period
• Pregnancy
• Intolerance to gluten, eggs, milk, yeast, nuts, or pea protein
• Missing consent to participate in the study
• Inability to understand the study content and procedures and to provide informed consent after appropriate explanation
• Persons institutionalized by court or administrative order
• Simultaneous participation in another interventional study

Sponsors & Collaborators

• Martin-Luther-Universität Halle-Wittenberg: lead

Study Sites (1)

University Hospital Martin-Luther-University Halle-Wittenberg

Halle, Saxony-Anhalt, D06120, Germany

Location

MeSH Terms

Conditions

Renal Insufficiency, Chronic

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Matthias Girndt, MD

  Martin-Luther-University Halle-Wittenberg

  STUDY DIRECTOR

Central Study Contacts

Matthias Girndt, MD

CONTACT

+49 345 557 2717; matthias.girndt@uk-halle.de

Roman Fiedler, MD

CONTACT

+49 345 582 970; roman.fiedler@uk-halle.de

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Head of the Department of Internal Medicine II

Study Record Dates

• First Submitted: April 8, 2026
• First Posted: April 22, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2028
• Last Updated: April 22, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1)