Fiber intake and health in people with chronic kidney disease Original paper
Researched by:
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Dr. Umar
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Dr. Umar
Read MoreClinical Pharmacist and Clinical Pharmacy Master’s candidate focused on antibiotic stewardship, AI-driven pharmacy practice, and research that strengthens safe and effective medication use. Experience spans digital health research with Bloomsbury Health (London), pharmacovigilance in patient support programs, and behavioral approaches to mental health care. Published work includes studies on antibiotic use and awareness, AI applications in medicine, postpartum depression management, and patient safety reporting. Developer of an AI-based clinical decision support system designed to enhance antimicrobial stewardship and optimize therapeutic outcomes.
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Dr. Umar
Read More
Researched by:
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Dr. Umar
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Dr. Umar
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Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Dr. Umar
What was reviewed?
This review article examined how dietary fiber intake influences health outcomes in people with chronic kidney disease (CKD), with particular attention to the microbiome signatures associated with fiber-driven modulation of gut microbial metabolism. It emphasized that low fiber intake is common in CKD, largely due to potassium-related dietary restrictions, yet higher fiber intake improves gut microbial balance by promoting saccharolytic (carbohydrate-fermenting) bacteria. This shift reduces proteolytic fermentation, subsequently lowering production of uremic toxins such as p-cresyl sulfate (pCS) and indoxyl sulfate (IS). The review highlights how fiber promotes short-chain fatty acid (SCFA) production, strengthens the intestinal barrier, reduces inflammation, improves transit, and indirectly supports renal health. These mechanisms form a microbiome-centered model linking dietary fiber to reduced toxin burden and better clinical outcomes.
Who was reviewed?
The review synthesized evidence from diverse populations with CKD across disease stages, including non-dialysis CKD (Stages 3–5), peritoneal dialysis, and hemodialysis cohorts. It incorporated randomized controlled trials, observational studies, and mechanistic research in humans and animals. Study populations ranged widely in geography (e.g., China, Sweden, Japan, Australia, Brazil, USA), dietary patterns, and baseline fiber intake. Many participants consumed less than 15 g/day of fiber—substantially below recommended levels—highlighting the clinical relevance of exploring fiber supplementation or plant-forward dietary patterns. The article also referenced general population datasets and diabetic cohorts to contextualize kidney-related outcomes.
Most important findings
Higher fiber intake consistently improves stool output, promotes saccharolytic fermentation, increases SCFA production, and supports gut barrier integrity. These changes reduce systemic inflammation, improve immune modulation, and lower circulating gut-derived toxins—effects visually detailed in the mechanistic models. Fiber-rich diets or prebiotic supplementation reduce pCS and IS levels, though the magnitude depends on fiber type, fermentability, dose, and site of colonic fermentation. Inulin-type fructans generally offer stronger uremic toxin reduction than rapidly fermented fibers like FOS. Observational data suggest that higher fiber intake may reduce CKD incidence, improve metabolic risk factors, lower cardiovascular mortality in dialysis cohorts, and reduce all-cause mortality. Constipation—prevalent in dialysis patients—improves reliably with increased fiber intake. However, long-term clinical trials examining CKD progression remain limited.
| Microbiome/Fiber Mechanism | Clinical Impact in CKD |
|---|---|
| Increased saccharolytic fermentation | Lower pCS and IS production |
| Higher SCFA generation (acetate, propionate, butyrate) | Reduced inflammation, improved gut barrier |
| Reduced proteolytic fermentation | Less nitrogenous waste and uremic toxins |
| Improved intestinal transit | Greater fecal excretion of toxins and potassium |
Key implications
Fiber intake represents a modifiable dietary variable with meaningful microbiome-mediated benefits for people with CKD. Its effects on microbial composition, SCFA production, intestinal permeability, and toxin generation offer a biologically coherent rationale for integrating fiber-rich foods or prebiotic supplementation into CKD nutrition care. The review argues that potassium concerns are often overstated and that plant-forward diets can be safely individualized. Clinicians should collaborate with dietitians to help patients adopt diverse, fiber-rich eating patterns that preserve renal and metabolic health while minimizing hyperkalemia risk. Future research should define optimal fiber types, doses, and long-term effects on CKD progression.
Citation
Su G, Qin X, Yang C, Sabatino A, Kelly JT, Avesani CM, Carrero JJ; ERA European Renal Nutrition Working Group. Fiber intake and health in people with chronic kidney disease. Clinical Kidney Journal. 2021;15(2):213-225. doi:10.1093/ckj/sfab169
Chronic Kidney Disease (CKD)
Dysbiosis in chronic kidney disease (CKD) reflects a shift toward reduced beneficial taxa and increased pathogenic, uremic toxin-producing species, driven by a bidirectional interaction in which the uremic environment disrupts microbial composition and dysbiotic metabolites accelerate renal deterioration.
Short-chain Fatty Acids (SCFAs)
Short-chain fatty acids are microbially derived metabolites that regulate epithelial integrity, immune signaling, and microbial ecology. Their production patterns and mechanistic roles provide essential functional markers within microbiome signatures and support the interpretation of MBTIs, MMAs, and systems-level microbial shifts across clinical conditions.