Overall conclusion
Probiotics represent a promising supportive treatment approach for CKD and related complications, with demonstrated benefits in toxin control, inflammation reduction, metabolic improvement, and kidney function protection. Nonetheless, larger and longer-term studies are required to determine optimal dosage, strains, and clinical outcome impacts.
Probiotic supplementation should be considered part of integrated care and prevention strategies for CKD progression.
1. https://pdfs.semanticscholar.org/faf8/71bd41bc697e02c54e39a7720e30a91d3fd6.pdf
2. https://pubs.acs.org/doi/10.1021/acs.jafc.4c00263
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC9613434/
4. https://www.sciencedirect.com/science/article/pii/S0085253815610067
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC6533949/
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC9571670/
7. https://www.sciencedirect.com/science/article/abs/pii/S2405457724015444
8. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1434613/full
9. https://www.tandfonline.com/doi/full/10.1080/0886022X.2022.2079522
10. https://nephropathol.com/Article/jnp-20180704100930
PART 2: SUMMARY OF BENEFITS OF PROBIOTICS FOR THE KIDNEY
Based on the references from Part 1, the most cited sources are :
1. Effectiveness in improving kidney function and reducing uremic toxins
Clinical studies and systematic reviews indicate that supplementation with probiotics/synbiotics significantly reduces blood urea nitrogen (BUN), C-reactive protein (CRP), and uremic toxins such as p-cresol and indoxyl sulfate in chronic kidney disease (CKD) patients, while slowing disease progression. Data show probiotics can lower BUN levels from 17.6 mmol/L to 14.2 mmol/L over 3 months, and improve gastrointestinal symptoms and quality of life in CKD patients.
2. Reduction of inflammation and immune regulation
Probiotics positively affect inflammatory markers in CKD patients, significantly lowering TNF-α, IL-6, IL-18, and endotoxin levels, while regulating overall immune response via reducing pro-inflammatory cytokines and increasing IgA antibodies, helping control chronic inflammation and preventing complications in CKD patients.
3. Enhancement of metabolism and nutritional indices
Probiotic supplementation improves blood glucose and lipid balance, and increases nutritional indicators such as serum protein and albumin in kidney disease patients, aiding metabolic complication control and maintaining patient condition. Some studies report albumin levels rising from 31.2 g/L to 34.1 g/L after 3 months of probiotics use.
4. Inhibition of kidney disease progression and renal structure protection
Several studies, including animal research and human trials, show probiotics contribute to delaying CKD progression, improving glomerular filtration function, and protecting microscopic kidney structures, maintaining normal tissue architecture under long-term toxin and inflammation exposure.
5. Positive effects on gut microbiota and protection of gut-kidney barrier
A key benefit is remodeling gut microbiota to reduce harmful bacteria, thus decreasing production of uremic toxins, protecting the gut-kidney barrier, and preventing systemic inflammation and metabolic complications.
6. Safety and recommendations for long-term use
Reviews confirm probiotics are generally safe and suitable for long-term use in CKD patients. However, effectiveness depends on dosage, bacterial strains, supplementation duration, and individual patient condition. To optimize efficacy, multi-strain formulations at appropriate doses maintained for at least 3 months are recommended in clinical studies.
PART 3: IN-DEPTH ANALYSIS OF SELECTED KEY REFERENCES
1. “Efficacy of probiotics/synbiotics supplementation in patients with chronic kidney disease: a systematic review and meta-analysis of randomized controlled trials”- Chang Liu, Letian Yang, Wei Wei, Ping Fu, Frontiers in Nutrition, 2024. [8]
- This is a systematic review and meta-analysis of 21 RCTs on the use of probiotics/synbiotics in patients with chronic kidney disease (CKD).
- The results indicate that probiotic/synbiotic supplementation significantly reduces blood urea nitrogen (BUN) and C-reactive protein (CRP) levels—key indicators of kidney function and inflammation in CKD patients (Results section, pp. 2–3).
- A more pronounced effect was observed with long-term supplementation. Some animal studies also showed that probiotics (especially Lactobacillus species) slow kidney disease progression and delay renal failure by modulating short-chain fatty acid and nicotinamide metabolism (pp. 4–5).
- Certain clinical studies demonstrated significant reductions in inflammatory markers such as TNF-α, IL-6, IL-18, and endotoxin following probiotic supplementation in CKD patients (p. 5).
- However, the authors concluded that larger-scale studies are needed to confirm the long-term benefits (Conclusion section, p. 5).
2. “Probiotics improve renal function, glucose, lipids, inflammation and oxidative stress in patients with diabetic kidney disease: a systematic review and meta-analysis of randomized controlled trials”- B.Y. Yang, Y.L. Deng, J.J. Qi, Y.F. Liu, L.L. Xu, Renal Failure (Taylor & Francis), 2022. [9]
- This meta-analysis, based on 10 RCTs, demonstrated that probiotics provide multiple metabolic benefits in patients with diabetic kidney disease, improving renal function (Scr, BUN, Cys-c, etc.), glucose and lipid balance, inflammation, and oxidative stress (pp. 2–3).
- More significant beneficial effects were observed with higher doses, multi-strain formulations, and longer intervention durations (subgroup analysis, p. 4).
- The paper calls for further long-term, multicenter studies to clarify clinical efficacy and safety, but already identifies probiotics as a promising, cost-effective strategy for renal and diabetic conditions (pp. 4–5).
3. “The Potential Benefits and Controversies of Probiotics Use in Patients with Chronic Kidney Disease”- N. Tian, X. X. Zhang, International Journal of Molecular Sciences (PMC), 2022. [6]
- This review discusses studies on the role of probiotics (mainly Lactobacillus and Bifidobacterium) in CKD patients, particularly their potential to reduce toxins, inflammation, and support symptom control and quality of life improvement (Abstract and pp. 1–2).
- In dialysis patients, some RCTs reported that probiotics reduce uremic toxin levels, improve digestive symptoms, lower inflammation, and decrease cardiovascular risks (pp. 2–3).
- However, results remain inconsistent, and there is still a lack of large-scale studies exploring dosage, duration, and effects on major clinical outcomes such as survival rates (pp. 3–4).
- Further research is recommended.
4. “Probiotics delay the decrease of kidney function in patients with chronic kidney disease (CKD)”, Siti Sapulette, Adila Azfar, et al., Proceedings of the International Conference on Nursing and Health Sciences, 2023. [1]
- This scoping review indicates that probiotics may slow CKD progression by modulating gut dysbiosis and reducing inflammation, emphasizing their clinical potential in improving renal function (pp. 3–4).
- The authors conclude that probiotics not only prevent but also partially restore kidney function (Conclusion, p. 4).
5. “Probiotics in the treatment of chronic kidney disease”, R.A.B. Fagundes, et al., Publisher: Brazilian Journal of Nephrology (PMC), 2018. [5]
- This review demonstrates that probiotics help reduce inflammatory markers (TNF-α, IL-6, IL-5, etc.) and endotoxin levels in CKD patients (p. 4).
- The main probiotic strains discussed are Lactobacillus and Bifidobacterium, which regulate immune responses and reduce pro-inflammatory cytokine production (pp. 3–4).
- Key benefits include symptom control and limiting kidney damage progression; however, definitive effects on creatinine and eGFR remain inconclusive (Conclusion, p. 5).
6. “Exploring the Preventive and Therapeutic Mechanisms of Probiotics in Chronic Kidney Disease”, H.W. Huang, et al., Publisher: Journal of Agricultural and Food Chemistry (ACS), 2024. [2]
- Probiotics are identified as a potential approach to regulate gut microbiota and reduce the production of nephrotoxic compounds, thereby helping to prevent CKD progression (Abstract, p. 1).
- The mechanisms involve modulation of short-chain fatty acid metabolism, nicotinamide pathways, and immune responses (pp. 2–3)./.