Production Of Uremic Toxins Research Articles

Identification of Gut Microbiota Involved in the Production of Uremic Toxins in Patients with CKD

Identification of Gut Microbiota Involved in the Production of Uremic Toxins in Patients with CKD

Effects of Propolis Supplementation on Gut Microbiota and Uremic Toxin Profiles of Patients Undergoing Hemodialysis.

Propolis possesses many bioactive compounds that could modulate the gut microbiota and reduce the production of uremic toxins in patients with chronic kidney disease (CKD) undergoing hemodialysis (HD). This clinical trial aimed to evaluate the effects of propolis on the gut microbiota profile and uremic toxin plasma levels in HD patients. These are secondary analyses from a previous double-blind, randomized clinical study, with 42 patients divided into two groups: the placebo and propolis group received 400 mg of green propolis extract/day for eight weeks. Indole-3 acetic acid (IAA), indoxyl sulfate (IS), and p-cresyl sulfate (p-CS) plasma levels were evaluated by reversed-phase liquid chromatography, and cytokines were investigated using the multiplex assay (Bio-Plex Magpix®). The fecal microbiota composition was analyzed in a subgroup of patients (n = 6) using a commercial kit for fecal DNA extraction. The V4 region of the 16S rRNA gene was then amplified by the polymerase chain reaction (PCR) using short-read sequencing on the Illumina NovaSeq PE250 platform in a subgroup. Forty-one patients completed the study, 20 in the placebo group and 21 in the propolis group. There was a positive correlation between IAA and TNF-α (r = 0.53, p = 0.01), IL-2 (r = 0.66, p = 0.002), and between pCS and IL-7 (r = 0.46, p = 0.04) at the baseline. No significant changes were observed in the values of uremic toxins after the intervention. Despite not being significant, microbial evenness and observed richness increased following the propolis intervention. Counts of the Fusobacteria species showed a positive correlation with IS, while counts of Firmicutes, Lentisphaerae, and Proteobacteria phyla were negatively correlated with IS. Two months of propolis supplementation did not reduce the plasma levels of uremic toxins (IAA, IS, and p-CS) or change the fecal microbiota.

Posttranslational modifications: an emerging functional layer of diet-host-microbe interactions.

The microbiome plays a vital role in human health, with changes in its composition impacting various aspects of the body. Posttranslational modification (PTM) regulates protein activity by attaching chemical groups to amino acids in an enzymatic or non-enzymatic manner. PTMs offer fast and dynamic regulation of protein expression and can be influenced by specific dietary components that induce PTM events in gut microbiomes and their hosts. PTMs on microbiome proteins have been found to contribute to host-microbe interactions. For example, in Escherichia coli, S-sulfhydration of tryptophanase regulates uremic toxin production and chronic kidney disease in mice. On a broader microbial scale, the microbiomes of patients with inflammatory bowel disease exhibit distinct PTM patterns in their metaproteomes. Moreover, pathogens and commensals can alter host PTM profiles through protein secretion and diet-regulated metabolic shifts. The emerging field of metaPTMomics focuses on understanding PTM profiles in the microbiota, their association with lifestyle factors like diet, and their functional effects on host-microbe interactions.

Compositional characteristics of the gut microbiome in patients with uremia.

During acute or chronic uremia, the cumulative harmful effects of uremic toxins result in numerous health problems and, ultimately, mortality. Previous research has identified that uremic retention solutes originate from the gut microbiome, indicating that uremia may be closely associated with gut microbiome dysbiosis. To deepen our understanding of the compositional characteristics of the gut microbiome in patients with uremia and thereby promote precision medicine in the treatment of uremia, we conducted a study of the compositional characteristics of the gut microbiome in 20 patients with uremia. The gut microbiome diversity of uremic patients and the control group showed certain differences. Nonmetric multidimensional scaling analysis showed that the beta diversity of the gut microbiome of uremic patients was significantly different from that of the healthy control individuals, with a distinct clustering effect in the uremic patient group, and it also showed a similarly distinct clustering effect in the healthy control group. The Chao1 index and Sobs index were significantly lower in the uremic patient group than in the healthy control group (P < 0.05). By analyzing the composition and abundance distribution of the gut microbiome in the uremic patient group and healthy control group, we found that the relative abundance of the gut microbiome constituents Fusobacteriota, Enterobacteriaceae, Oscillospirales, Ruminococcaceae, and Lachnospiraceae was significantly increased in the intestines of uremic patients. We also detected the rare taxa Erysipelotrichaceae, which was present only in the uremic patient group. Predictive functional analysis suggested that an increased abundance of Ruminococcaceae and Lachnospirales, which are associated with indoxyl sulfate and phenylacetyl glutamine, and an increased abundance of Oscillospirales, which is associated with pyruvate metabolism, in uremic patients may strongly influence the gut environment according to renal function, resulting in dysbiosis associated with uremic toxin production. Rare taxa such as Erysipelotrichaceae have been suggested to be detrimental to intestinal disease. Further research into these gut microbiomes may provide new ideas for the prevention and treatment of uremia with the gut microbiome.

7-Phenylheptanoic Acid-Hydroxypropyl β-Cyclodextrin Complex Slows the Progression of Renal Failure in Adenine-Induced Chronic Kidney Disease Mice.

The characteristic accumulation of circulating uremic toxins, such as indoxyl sulfate (IS), in chronic kidney disease (CKD) further exacerbates the disease progression. The gut microbiota, particularly gut bacterial-specific enzymes, represents a selective and attractive target for suppressing uremic toxin production and slowing the progression of renal failure. This study investigates the role of 4-phenylbutyrate (PB) and structurally related compounds, which are speculated to possess renoprotective properties in suppressing IS production and slowing or reversing renal failure in CKD. In vitro enzyme kinetic studies showed that 7-phenylheptanoic acid (PH), a PB homologue, suppresses the tryptophan indole lyase (TIL)-catalyzed decomposition of tryptophan to indole, the precursor of IS. A hydroxypropyl β-cyclodextrin (HPβCD) inclusion complex formulation of PH was prepared to enhance its biopharmaceutical properties and to facilitate in vivo evaluation. Prophylactic oral administration of the PH-HPβCD complex formulation reduced circulating IS and attenuated the deterioration of renal function and tubulointerstitial fibrosis in adenine-induced CKD mice. Additionally, treatment of moderately advanced adenine-induced CKD mice with the formulation ameliorated renal failure, although tissue fibrosis was not improved. These findings suggest that PH-HPβCD can slow the progression of renal failure and may have implications for preventing or managing CKD, particularly in early-stage disease.

A case of chronic kidney disease with refractory periodic vomiting and hypertension in a pediatric patient.

Patients with chronic kidney disease (CKD) sometimes experience gastrointestinal symptoms, such as nausea and vomiting. In addition, hypertension and CKD are closely linked, and sustained hypertension in children is associated with the progression of CKD, leading to early cardiomyopathy and premature atherosclerosis. These symptoms substantially affect the quality of daily life of CKD patients, and particularly in children with CKD, they may cause growth retardation. Therefore, establishing effective management methods to alleviate these symptoms is very important. Here, we report a case of a male patient who was born at 34weeks of gestation weighing 1400g. At birth, abdominal ultrasonography displayed left multicystic dysplastic kidney. From 6months after birth, he was frequently hospitalized owing to refractory periodic vomiting. At 9 months old, he was diagnosed as having stage 3a CKD, and at 20 months old, he presented with stage 2 high blood pressure. In Japan, the uremic toxin adsorbent AST-120 and angiotensin-converting enzyme inhibitor-I (ACE-I) are not strongly recommended for CKD patients. However, after the patient underwent combination therapy of AST-120 and ACE-I, his frequent hospitalizations for refractory periodic vomiting ceased, and his blood pressure decreased. These results indicate that AST-120 and ACE-I are effective for refractory periodic vomiting and hypertension associated with CKD. The patient's height, weight, and mental development are catching up smoothly. The cause of the patient's refractory periodic vomiting remains unclear. However, his impaired kidney function owing to congenital anomalies of the kidney and urinary tract may have caused the refractory periodic vomiting and dehydration. The production of uremic toxins in CKD patients is thought to lead to the secretion of proinflammatory cytokines into the circulation. However, our patient had low serum levels of proinflammatory cytokines, and his serum levels of the chemokines CX3CL1 and CCL2 decreased with age, together with improvement in his clinical course. Therefore, some specific chemokines might be diagnostic and/or prognostic biomarkers of CKD.

Gut microbiota dysbiosis in hyperuricaemia promotes renal injury through the activation of NLRP3 inflammasome

BackgroundThe prevalence of hyperuricaemia (HUA), a metabolic disorder characterized by elevated levels of uric acid, is on the rise and is frequently associated with renal injury. Gut microbiota and gut-derived uremic toxins are critical mediators in the gut-kidney axis that can cause damage to kidney function. Gut dysbiosis has been implicated in various kidney diseases. However, the role and underlying mechanism of the gut microbiota in HUA-induced renal injury remain unknown.ResultsA HUA rat model was first established by knocking out the uricase (UOX). HUA rats exhibited apparent renal dysfunction, renal tubular injury, fibrosis, NLRP3 inflammasome activation, and impaired intestinal barrier functions. Analysis of 16S rRNA sequencing and functional prediction data revealed an abnormal gut microbiota profile and activation of pathways associated with uremic toxin production. A metabolomic analysis showed evident accumulation of gut-derived uremic toxins in the kidneys of HUA rats. Furthermore, faecal microbiota transplantation (FMT) was performed to confirm the effects of HUA-induced gut dysbiosis on renal injury. Mice recolonized with HUA microbiota exhibited severe renal injury and impaired intestinal barrier functions following renal ischemia/reperfusion (I/R) surgery. Notably, in NLRP3-knockout (NLRP3−/−) I/R mice, the deleterious effects of the HUA microbiota on renal injury and the intestinal barrier were eliminated.ConclusionOur results demonstrate that HUA-induced gut dysbiosis contributes to the development of renal injury, possibly by promoting the production of gut-derived uremic toxins and subsequently activating the NLRP3 inflammasome. Our data suggest a potential therapeutic strategy for the treatment of renal diseases by targeting the gut microbiota and the NLRP3 inflammasome.-txnFZYkVzJbh2g8RkPjrkVideo Graphical

Dietary Phosphorus Levels Influence Protein-Derived Uremic Toxin Production in Nephrectomized Male Rats.

Gut microbiota-derived uremic toxins (UT) accumulate in patients with chronic kidney disease (CKD). Dietary phosphorus and protein restriction are common in CKD treatment, but the relationship between dietary phosphorus, a key nutrient for the gut microbiota, and protein-derived UT is poorly studied. Thus, we explored the relationship between dietary phosphorus and serum UT in CKD rats. For this exploratory study, we used serum samples from a larger study on the effects of dietary phosphorus on intestinal phosphorus absorption in nephrectomized (Nx, n = 22) or sham-operated (sham, n = 18) male Sprague Dawley rats. Rats were randomized to diet treatment groups of low or high phosphorus (0.1% or 1.2% w/w, respectively) for 1 week, with serum trimethylamine oxide (TMAO), indoxyl sulfate (IS), and p-cresol sulfate (pCS) analyzed by LC-MS. Nx rats had significantly higher levels of serum TMAO, IS, and pCS compared to sham rats (all p < 0.0001). IS showed a significant interaction between diet and CKD status, where serum IS was higher with the high-phosphorus diet in both Nx and sham rats, but to a greater extent in the Nx rats. Serum TMAO (p = 0.24) and pCS (p = 0.34) were not affected by dietary phosphorus levels. High dietary phosphorus intake for 1 week results in higher serum IS in both Nx and sham rats. The results of this exploratory study indicate that reducing dietary phosphorus intake in CKD may have beneficial effects on UT accumulation.

#883 P-cresyl sulphate and Indoxyl sulphate: two uremic toxins stimulating colon cancer progression in patients with chronic renal failure

Abstract Background and Aims Chronic kidney disease (CKD) leads to the accumulation and production of uremic toxins, such as Indoxyl Sulphate (IS) and P-cresyl sulphate (p-CS). These toxins have been found to activate various processes that promote tumor growth. The literature has reported a two-fold increase in the incidence of colon cancer (CRC) and a worse prognosis in CKD patients, although the specific mechanisms underlying this association have not been fully elucidated. Given the pro-oncogenic activities of p-CS and IS at both the systemic and intestinal levels, it is plausible that these toxins contribute to the heightened aggressiveness of CRC in CKD patients. Method In order to assess the impact of toxins detected in uremic patients, we conducted experiments using three different colorectal cancer (CRC) cell lines (HT29, Hct116, LoVo). We tested various concentrations of IS and p-CS and measured their effects on tumor cell proliferation through a colorimetric assay called WST-8. For further analysis of cell survival, we performed a clonogenic assay. To investigate the migratory abilities of tumor cells after toxins treatment, we conducted a wound healing assay. Additionally, we assessed the invasive capacities of the three CRC cell lines post treatment with IS and p-CS using an invasion assay. In order to identify the specific pathways affected by toxins exposure, we conducted Real Time PCR and Western blot analysis to evaluate the inflammatory pathway and the epithelial-mesenchymal transition (EMT), respectively. Results The results of this study are remarkable, as we observed a notable increase in cell growth after exposure of cultured cells to various concentrations of toxins, as compared to the control group. Furthermore, the concentrations of IS and p-CS induced a substantial enhancement in cell migration and invasion. In the case of HCT116 cells treated with uremic toxins, there was an up-regulation of Vimentin protein expression, while E-cadherin expression was down-regulated compared to the control group. These proteins are crucial in the process of Epithelial-Mesenchymal Transition (EMT). Additionally, we evaluated the expression of genes associated with the inflammatory process (TNF-alpha, INOS, and IL-6) in the HT-29 and LoVo cell lines. Interestingly, we observed an up-regulation of these genes. Of particular importance, in the LoVo cell line, IL-6 exhibited the most significant increase in expression. Conclusion Based on these preliminary results, it appears that IS and p-CS play a key role in the progression of CRC in patients with CKD.

Production of Toxins by the Gut Microbiota: The Role of Dietary Protein.

This narrative review will discuss how the intake of specific protein sources (animal and vegetable) providing specific amino acids can modulate the gut microbiota composition and generate toxins. A better understanding of these interactions could lead to more appropriate dietary recommendations to improve gut health and mitigate the risk of complications promoted by the toxic metabolites formed by the gut microbiota. Gut microbiota is vital in maintaining human health by influencing immune function and key metabolic pathways. Under unfavorable conditions, the gut microbiota can produce excess toxins, which contribute to inflammation and the breakdown of the integrity of the intestinal barrier. Genetic and environmental factors influence gut microbiota diversity, with diet playing a crucial role. Emerging evidence indicates that the gut microbiota significantly metabolizes amino acids from dietary proteins, producing various metabolites with beneficial and harmful effects. Amino acids such as choline, betaine, l-carnitine, tyrosine, phenylalanine, and tryptophan can increase the production of uremic toxins when metabolized by intestinal bacteria. The type of food source that provides these amino acids affects the production of toxins. Plant-based diets and dietary fiber are associated with lower toxin formation than animal-based diets due to the high amino acid precursors in animal proteins.

Uremic toxins mediate kidney diseases: the role of aryl hydrocarbon receptor.

Aryl hydrocarbon receptor (AhR) was originally identified as an environmental sensor that responds to pollutants. Subsequent research has revealed that AhR recognizes multiple exogenous and endogenous molecules, including uremic toxins retained in the body due to the decline in renal function. Therefore, AhR is also considered to be a uremic toxin receptor. As a ligand-activated transcriptional factor, the activation of AhR is involved in cell differentiation and senescence, lipid metabolism and fibrogenesis. The accumulation of uremic toxins in the body is hazardous to all tissues and organs. The identification of the endogenous uremic toxin receptor opens the door to investigating the precise role and molecular mechanism of tissue and organ damage induced by uremic toxins. This review focuses on summarizing recent findings on the role of AhR activation induced by uremic toxins in chronic kidney disease, diabetic nephropathy and acute kidney injury. Furthermore, potential clinical approaches to mitigate the effects of uremic toxins are explored herein, such as enhancing uremic toxin clearance through dialysis, reducing uremic toxin production through dietary interventions or microbial manipulation, and manipulating metabolic pathways induced by uremic toxins through controlling AhR signaling. This information may also shed light on the mechanism of uremic toxin-induced injury to other organs, and provide insights into clinical approaches to manipulate the accumulated uremic toxins.

Food to Prevent Vascular Calcification in Chronic Kidney Disease.

Vascular calcification (VC) is a consequence of chronic kidney disease (CKD) which is of paramount importance regarding the survival of CKD patients. VC is far from being controlled with actual medication; as a result, in recent years, diet modulation has become more compelling. The concept of medical nutritional therapy points out the idea that food may prevent or treat diseases. The aim of this review was to evaluate the influence of food habits and nutritional intervention in the occurrence and progression of VC in CKD. Evidence reports the harmfulness of ultra-processed food, food additives, and animal-based proteins due to the increased intake of high absorbable phosphorus, the scarcity of fibers, and the increased production of uremic toxins. Available data are more supportive of a plant-dominant diet, especially for the impact on gut microbiota composition, which varies significantly depending on VC presence. Magnesium has been shown to prevent VC but only in experimental and small clinical studies. Vitamin K has drawn considerable attention due to its activation of VC inhibitors. There are positive studies; unfortunately, recent trials failed to prove its efficacy in preventing VC. Future research is needed and should aim to transform food into a medical intervention to eliminate VC danger in CKD.

Impact of synbiotics on uremic toxins production, renal function and protein energy wasting syndrome: In vitro and in vivo study

Impact of synbiotics on uremic toxins production, renal function and protein energy wasting syndrome: In vitro and in vivo study

Gut Microbiota Interventions to Retain Residual Kidney Function.

Residual kidney function for patients with chronic kidney disease (CKD) is associated with better quality of life and outcome; thus, strategies should be implemented to preserve kidney function. Among the multiple causes that promote kidney damage, gut dysbiosis due to increased uremic toxin production and endotoxemia need attention. Several strategies have been proposed to modulate the gut microbiota in these patients, and diet has gained increasing attention in recent years since it is the primary driver of gut dysbiosis. In addition, medications and faecal transplantation may be valid strategies. Modifying gut microbiota composition may mitigate chronic kidney damage and preserve residual kidney function. Although various studies have shown the influential role of diet in modulating gut microbiota composition, the effects of this modulation on residual kidney function remain limited. This review discusses the role of gut microbiota metabolism on residual kidney function and vice versa and how we could preserve the residual kidney function by modulating the gut microbiota balance.

The Usefulness of Resistant Maltodextrin and Chitosan Oligosaccharide in Management of Gut Leakage and Microbiota in Chronic Kidney Disease.

Microbiota-dysbiosis-induced gut leakage is a pathophysiologic change in chronic kidney disease (CKD), leading to the production of several uremic toxins and their absorption into the bloodstream to worsen the renal complications. We evaluate the benefits of resistant maltodextrin (RMD) and chitosan oligosaccharide (COS) supplements in cell culture and CKD-induced rats. The RMD exerted a significant anti-inflammatory effect in vitro and intestinal occludin and zonula occluden-1 up-regulation in CKD rats compared with inulin and COS. While all prebiotics slightly improved gut dysbiosis, RMD remarkably promoted the relative abundance and the combined abundance of Lactobacillus, Bifidobacteria, Akkermansia, and Roseburia in CKD rats. Supplements of RMD should be advantageous in the treatment of gut leakage and microbiota dysbiosis in CKD.

Gut dysbiosis and the role of probiotics in chronic kidney disease

Chronic inflammatory condition in chronic kidney disease (CKD) patients is associated with increased risk of cardiovascular morbidity and mortality. Gut dysbiosis is assumed as one of leading factors to the chronic inflammatory condition. The relationship between the kidney and the gastrointestinal, knowns as the gut-kidney axis, has a role in production and accumulation of uremic toxins derived from gut microbial fermentation of protein, and translocation of endotoxins and microbial from gut lumen into bloodstream due to alterations of intestinal epithelial barrier in CKD patients. Probiotics supplementation is one of the optional theraphy to restore the gut dysbiosis in CKD patients. Recent studies found that probiotics supplementation in CKD patients decreased uremic toxins and pro-inflammatory cytokines production, and delayed CKD progression. The improvement of this chronic inflammatory condition is expected to decrease cardiovascular disease risk in CKD patients. This review aims to describe the importance of gut-kidney axis in CKD patients, particularly in gut dysbiosis, and the role of probiotics in progression of CKD.

Branched-chain ketoacid co-ingestion with protein lowers amino acid oxidation during hemodialysis: A randomized controlled cross-over trial

Hemodialysis removes amino acids from the circulation, thereby stimulating muscle proteolysis. Protein ingestion during hemodialysis can compensate for amino acid removal but may also increase uremic toxin production. Branched-chain ketoacid (BCKA) co-ingestion may provide an additional anabolic stimulus without adding to uremic toxin accumulation. In the present study we assessed the impact of BCKA co-ingestion with protein on forearm amino acid balance and amino acid oxidation during hemodialysis. Nine patients (age: 73±10y) on chronic hemodialysis participated in this crossover trial. During two 4-h hemodialysis sessions, patients ingested 18g protein with (PRO+BCKA) or without (PRO) 9g BCKAs in a randomized order. Test beverages were labeled with L-[ring-13C6]-phenylalanine and provided throughout the last 3h of hemodialysis as 18 equal sips consumed with 10-min intervals. Arterial and venous plasma as well as breath samples were collected frequently throughout hemodialysis. Arterial plasma total amino acid (TAA) concentrations during PRO and PRO+BCKA treatments were significantly lower after 1h of hemodialysis (2.6±0.3 and 2.6±0.3mmol/L, respectively) when compared to pre-hemodialysis concentrations (4.2±1.0 and 4.0±0.5mmol/L, respectively; time effect: P<0.001). Arterial plasma TAA concentrations increased throughout test beverage ingestion (time effect: P=0.027) without differences between treatments (time∗treatment: P=0.62). Forearm arteriovenous TAA balance during test beverage ingestion did not differ between timepoints (time effect: P=0.31) or treatments (time∗treatment: P=0.34). Whole-body phenylalanine oxidation was 33±16% lower during PRO+BCKA when compared to PRO treatments (P<0.001). BCKA co-ingestion with protein during hemodialysis does not improve forearm net protein balance but lowers amino acid oxidation.

Role of Dietary Fibers in Chronic Kidney Disease Patients

Dietary fibers are predominantly plant based carbohydrates which requires microbial activity for their breakdown in gut through anaerobic fermentation yielding short chain fatty acids. Despite being recognized as lacking nutritional values, Dietary fibers are considered important predominantly due to it&amp;#39;s beneficial effects on blood pressure, glycemic control, lipid profile, body weight, inflammation and metabolic acidosis. Also, By modulation of gut dysbiosis secondary to diet-microbe-host interactions, It decreases uremic toxin production and it&amp;#39;s permeability in chronic kidney disease patients. Due to these beneficial effects, Dietary fibers are considered to impact morbidity, progression of disease, decrease in cardiovascular complications leading to mortality in Chronic kidney disease patients. We are going to discuss the classification, dosing, beneficial effects, supporting evidences and recommendations pertaining to dietary fibers in chronic kidney disease in this article.

#3454 IMPACT OF SYMBIOTICS ON UREMIC TOXINS PRODUCTION, RENAL FUNCTION AND PEW SYNDROME IN SHIME AND CKD MICE MODELS

Abstract Background and Aims Alterations in gut microbiota in CKD patients have been linked to CKD progression, cachexia, and mortality. Gut dysbiosis is associated by modification of gut-microbiota-derived metabolites, including a decrease of short-chain fatty acids (SCFAs), an increase in gut-derived uremic toxins. Therefore, modulation of gut microbiota seems to be an attractive therapeutic approach. In silico studies led to the selection of bacterial species able to increase SCFAs production, improve gut function without having the enzymatic machinery for producing uremic toxins. The propose of this study is to indentify the impact of two different symbiotics containing the selected bacteria: 1) on both uremic toxins and SCFAs production using a Simulator of the Human Intestinal Microbial Ecosystem (SHIME) colonized with fresh feces from CKD or healthy controls (HC) and subsequently 2) on renal function, metabolic parameters, intestinal microbiota and gut-microbiota-derived metabolites in a mouse model of CKD (5/6 nephrectomy). Method 1) The SHIME® system manufactured by ProDigest (Ghent, Belgium) consists of systems comprising five double-wall biovessels simulating the stomach (ST), small intestine (SI), ascending colon (AC), transverse colon (TC), and descending colon (DC). The supernatant of the homogenized fecal slurry was inoculated into the AC (25 mL), TC (40 mL), and DC (30 mL), respectively. After fecal inoculation, SHIME system were fed in ST twice day with two different symbiotics (P1 or P2) for 10 days. After 7 days, we applied a diet amino acid (AA) challenge to all the groups. SCFAs and uremic toxins were quantified every day. 2) CKD mice received either P1 or P2 admix for 6 weeks. We measured food intake, body composition and renal function including renal fibrosis quantification. Plasma metabolomic and feces metagenomic analyses were performed. Results In vitro, the concentration of precursor of uremic toxins (indols and p-cresol) tended to be higher in DC colonized by feces from CKD patients and AA challenge increased uremic toxins production more significantly in CKD compared to HC. CKD microbiome showed a lower butyrate concentration at baseline and higher propionate and acetate production. Both P1 and P2 significantly limited uremic toxins production during AA challenge and increase SCFA production. In vivo, both symbiotics increased body weight (+14%) and food intake (+31%) compared to CKD mice on chow diet. Treatment did not impact lipid or glucose metabolism but fat accretion in epididymal was restored with P1. Both diets, but particularly P1, significantly reduced plasmatic urea, proteinuria, and kidney fibrosis. Symbiotics improved intestinal barrier with a greater expression of Occludin in the ileum. Metagenomic analyses of the gut microbiota indicated that the alfa-diversity was not different across groups while the beta-diversity was similar to the sham group if CKD mice were treated with symbiotics. Both symbiotics reduced significantly plasma levels of deleterious uremic toxins such as p-cresyl sulfate and indoxyl sulfate and symbiotics reduce fecal module of trypotophan degradation and other modules related to AA metabolism. Both diets increased fecal bacteria modules related to SCFAs production. Conclusion We have shown both in vitro and in vivo that a symbiotic association can reduce uremic toxins production and increase SCFA production by inducing a significant change in gut microbiota composition and function. These metabolic changes are associated with improved appetite, decreased uremic cachexia, and preserved renal function. This data needs be confirmed in a human clinical trial.

#4484 EFFECT OF BROCCOLI SPROUT EXTRACT IN PATIENTS WITH TYPE 2 DIABETES AND CHRONIC KIDNEY DISEASE (INITIATE) - DESIGN AND BASELINE DATA

Abstract Background and Aims In advanced stages of chronic kidney disease (CKD) some glucose-lowering agents, such as metformin, cannot be prescribed to patients with type 2 diabetes (T2D) due to the risk of accumulation and adverse events. Foods with bioactive components, “functional food”, can be an alternative to mitigate the metabolic disturbances in these patients. Previous research on experimental animals and patients with T2D has shown that sulforaphane, present in broccoli sprouts, improves insulin sensitivity and glucose control. We hypothesize that sulforaphane ingested as a broccoli sprout extract (BSE) can improve glucose control in patients with T2D and CKD. Method This is an ongoing multicentre randomized double-blinded controlled trial with glucose control as the primary outcome. Glucose control is evaluated by fasting serum glucose, serum insulin in all patients, and oral glucose tolerance test (OGTT) in patients not on insulin treatment. Moreover, as a secondary aim, we investigate the role of BSE in improving other signs of metabolic alterations, including oxidative stress, proteinuria, inflammation and production of uremic toxins from the gut microbiota. Patients: Adult patients with T2D and CKD (eGFR 15- 45 ml/min/1.73m2) are included and randomized 1:1 to receive BSE or placebo. Both groups are followed for 20 weeks. The first 12 weeks, patients receive BSE or placebo and are then followed for 8 weeks. Patients randomized to BSE receive an increasing dose of sulforaphane administered as BSE (Lantmännen®) starting with 50 µmmol/day in week 0 - 4; 100 µmmol/day in week 5 - 8 and 150 µmmol/day in week 9 - 12. The placebo consists of maltodextrin sprayed with copper-chlorophyllin. Blood and urine laboratory measurements and OGTT is performed at week 0, 12 and 20. Randomization is done using a computer-based block randomization algorithm. The protocol is registered at clinicaltrials.gov (NCT04858854). Results 98 patients with T2D and CKD from 12 centers in Sweden were included and the recruiting phase has now been finalized but the follow up phase is still ongoing. We here present baseline characteristics of all study participants (Table 1). Median age is 75 years and a minority are women. Mean eGFR corresponds to CKD stage 4 and there are large variations in albumin/creatinine ratios. Most participants are on a combination of oral glucose-lowering agents and insulin. A history of cardiovascular disease is common, and 21% had a previously had myocardial infarction. Conclusion We are currently conducting a randomized clinical trial testing if BSE can be used as an alternative or add-on to improve glucose control in patients with T2D and CKD stages 3-4 type and to see if this ‘high risk’ patient group could benefit from treatment with BSE.