Adsorption-Based Strategies for Removing Uremic Toxins from Blood

Background: Bacterial metabolism contributes to the generation of uremic toxins in patients with chronic kidney disease (CKD). It has been investigated the use of probiotics in the reduction of uremic toxins intestinal production. Objective: The aim of this pilot study was to evaluate the effect of probiotic supplementation on reducing the production of uremic toxins and the inflammatory profile of CKD patients. Methods: We performed a randomized, blind, placebo-controlled, crossover study on patients with CKD stages 3 and 4. The intervention was a probiotic formulation composed of Lactobacillus acidophilus strains given orally three times a day for 3 months. Changes in uremic toxins (p-Cresylsulfate and Indoxyl Sulfate) and serum inflammatory cytokines were the primary endpoints. Results: Of the 44 patients randomized, 25 completed the study (mean age 51 ± 9.34, 64% female, mean eGFR 36 ± 14.26 mL/min/1.73m², mean BMI 28.5 ± 5.75 kg/m²). At 3 months, there were no significant changes in any of the studied biomarkers including p-cresylsulfate (p = 0.57), Indoxyl sulfate (p = 0.08) and interleukin-6 (p = 0.55). Conclusion: Lactobacillus acidophilus strains given as probiotic were not able to reduce serum levels of uremic toxins and biomarkers of inflammation in CKD patients in stage 3 and 4.

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Role of uremic toxins in exacerbating anemia in renal failure

Kidney International ◽

10.1046/j.1523-1755.2001.07821.x ◽

2001 ◽

Vol 59 (s78) ◽

pp. 67-72 ◽

Cited By ~ 30

Author(s):

Iain C. Macdougall

Keyword(s):

Renal Failure ◽

Uremic Toxins

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Uremic toxins and peritoneal dialysis

Kidney International ◽

10.1046/j.1523-1755.2001.07820.x ◽

2001 ◽

Vol 59 (s78) ◽

pp. 292-297 ◽

Cited By ~ 14

Author(s):

Norbert Lameire ◽

Raymond Vanholder ◽

Rita De Smet

Keyword(s):

Peritoneal Dialysis ◽

Uremic Toxins

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Uremic Toxins and Their Relation with Oxidative Stress Induced in Patients with CKD

International Journal of Molecular Sciences ◽

10.3390/ijms22126196 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6196

Author(s):

Anna Pieniazek ◽

Joanna Bernasinska-Slomczewska ◽

Lukasz Gwozdzinski

Keyword(s):

Oxidative Stress ◽

Uremic Toxins ◽

Water Medium ◽

Induce Insulin Resistance ◽

Risk Of Mortality ◽

Increased Risk ◽

Stage Renal Disease ◽

End Stage

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.

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Contribution of Gut Microbiota-Derived Uremic Toxins to the Cardiovascular System Mineralization

Toxins ◽

10.3390/toxins13040274 ◽

2021 ◽

Vol 13 (4) ◽

pp. 274

Author(s):

Iwona Filipska ◽

Agata Winiarska ◽

Monika Knysak ◽

Tomasz Stompór

Keyword(s):

Kidney Disease ◽

Gut Microbiota ◽

Mineral Content ◽

Uremic Toxins ◽

World Population ◽

Uremic Toxin ◽

Excess Morbidity ◽

The Media ◽

Cardio Vascular ◽

End Stage

Chronic kidney disease (CKD) affects more than 10% of the world population and leads to excess morbidity and mortality (with cardiovascular disease as a leading cause of death). Vascular calcification (VC) is a phenomenon of disseminated deposition of mineral content within the media layer of arteries preceded by phenotypic changes in vascular smooth muscle cells (VSMC) and/or accumulation of mineral content within the atherosclerotic lesions. Medial VC results in vascular stiffness and significantly contributes to increased cardio-vascular (CV) morbidity, whereas VC of plaques may rather increase their stability. Mineral and bone disorders of CKD (CKD-MBD) contribute to VC, which is further aggravated by accumulation of uremic toxins. Both CKD-MBD and uremic toxin accumulation affect not only patients with advanced CKD (glomerular filtration rate (GFR) less than 15 mL/min./1.72 m2, end-stage kidney disease) but also those on earlier stages of a disease. The key uremic toxins that contribute to VC, i.e., p-cresyl sulphate (PCS), indoxyl sulphate (IS) and trimethylamine-N-oxide (TMAO) originate from bacterial metabolism of gut microbiota. All mentioned toxins promote VC by several mechanisms, including: Transdifferentiation and apoptosis of VSMC, dysfunction of endothelial cells, oxidative stress, interaction with local renin–angiotensin–aldosterone system or miRNA profile modification. Several attractive methods of gut microbiota manipulations have been proposed in order to modify their metabolism and to limit vascular damage (and VC) triggered by uremic toxins. Unfortunately, to date no such method was demonstrated to be effective at the level of “hard” patient-oriented or even clinically relevant surrogate endpoints.

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Uremic toxins levels from the gut microbiota seem not to be altered by physical exercise in hemodialysis patients

International Urology and Nephrology ◽

10.1007/s11255-021-02945-0 ◽

2021 ◽

Author(s):

Jessyca Sousa de Brito ◽

Drielly Vargas ◽

Greicielle Santos da Silva ◽

Sandra Marinho ◽

Natália Alvarenga Borges ◽

...

Keyword(s):

Physical Exercise ◽

Gut Microbiota ◽

Hemodialysis Patients ◽

Uremic Toxins

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Uremic Toxins and Frailty in Patients with Chronic Kidney Disease: A Molecular Insight

International Journal of Molecular Sciences ◽

10.3390/ijms22126270 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6270

Author(s):

Chia-Ter Chao ◽

Shih-Hua Lin

Keyword(s):

Chronic Kidney Disease ◽

Renal Function ◽

Kidney Disease ◽

Uremic Toxins ◽

Heme Oxygenase 1 ◽

Signal Pathways ◽

Uremic Toxin ◽

Nuclear Factor ◽

Cognitive Frailty ◽

Renal Function Decline

The accumulation of uremic toxins (UTs) is a prototypical manifestation of uremic milieu that follows renal function decline (chronic kidney disease, CKD). Frailty as a potential outcome-relevant indicator is also prevalent in CKD. The intertwined relationship between uremic toxins, including small/large solutes (phosphate, asymmetric dimethylarginine) and protein-bound ones like indoxyl sulfate (IS) and p-cresyl sulfate (pCS), and frailty pathogenesis has been documented recently. Uremic toxins were shown in vitro and in vivo to induce noxious effects on many organ systems and likely influenced frailty development through their effects on multiple preceding events and companions of frailty, such as sarcopenia/muscle wasting, cognitive impairment/cognitive frailty, osteoporosis/osteodystrophy, vascular calcification, and cardiopulmonary deconditioning. These organ-specific effects may be mediated through different molecular mechanisms or signal pathways such as peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), mitogen-activated protein kinase (MAPK) signaling, aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Runt-related transcription factor 2 (RUNX2), bone morphogenic protein 2 (BMP2), osterix, Notch signaling, autophagy effectors, microRNAs, and reactive oxygen species induction. Anecdotal clinical studies also suggest that frailty may further accelerate renal function decline, thereby augmenting the accumulation of UTs in affected individuals. Judging from these threads of evidence, management strategies aiming for uremic toxin reduction may be a promising approach for frailty amelioration in patients with CKD. Uremic toxin lowering strategies may bear the potential of improving patients’ outcomes and restoring their quality of life, through frailty attenuation. Pathogenic molecule-targeted therapeutics potentially disconnect the association between uremic toxins and frailty, additionally serving as an outcome-modifying approach in the future.

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