Uremic Toxins and Cardiovascular Risk in Chronic Kidney Disease: What Have We Learned Recently beyond the Past Findings?

Unveiling the microbiota-metabolite-myocardium axis: a novel perspective on cardiovascular health

Introduction

Cardiovascular diseases, including myocardial infarction, remain a leading cause of death globally. Emerging evidence suggests the gut microbiota plays a crucial role in cardiovascular health. This study aims to explore the impact of gut microbiota on myocardial infarction using a mouse model.

Methods

The research utilizes a multi-omics approach, including 16S rDNA sequencing and LC-MS-based metabolomics to analyze fecal and serum samples from mice modeled to mimic myocardial infarction. This methodology allows for a comprehensive analysis of microbial populations and their metabolic output.

Results

The findings reveal a significant reduction in gut microbiota α-diversity in mice with induced myocardial infarction compared to healthy controls. Notably, there is an increase in populations of Fusobacteria and Clostridia. Metabolomic analysis indicates disruptions in amino acid and energy metabolism, suggesting a metabolic dysregulation linked to myocardial health.

Discussion

The study proposes a novel microbiota-metabolite-myocardium axis, where specific microbial metabolites may directly affect heart health. This connection points to the gut microbiota as a potential player in the pathogenesis of myocardial infarction and may open new therapeutic avenues targeting the gut microbiome to combat cardiovascular diseases.

Study of the association between serum levels of kynurenine and cardiovascular outcomes and overall mortality in chronic kidney disease

Background

Kynurenine is a protein-bound uremic toxin. Its circulating levels are increased in chronic kidney disease (CKD). Experimental studies showed that it exerted deleterious cardiovascular effects. We sought to evaluate an association between serum kynurenine levels and adverse fatal or nonfatal cardiovascular events and all-cause mortality in CKD patients.

Methods

The CKD-REIN study is a prospective cohort of people with CKD having an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m². Baseline frozen samples of total and free fractions of kynurenine and tryptophan were measured using a validated liquid chromatography tandem mass spectrometry technique. Cause-specific Cox models were used to estimate hazard ratios (HRs) for each outcome.

Results

Of the 2406 included patients (median age: 68 years; median eGFR: 25 ml/min/1.73 m2), 52% had a history of cardiovascular disease. A doubling of serum-free kynurenine levels was associated with an 18% increased hazard of cardiovascular events [466 events, HR (95%CI):1.18(1.02,1.33)], independently of eGFR, serum-free tryptophan level or other uremic toxins, cardioprotective drugs, and traditional cardiovascular risk factors. Serum-free kynurenine was significantly associated with non-atheromatous cardiovascular events [HR(95%CI):1.26(1.03,1.50)], but not with atheromatous cardiovascular events [HR(95%CI):1.15(0.89,1.50)]. The association of serum-free kynurenine with cardiovascular mortality was also independently significant [87 events; adjusted HR(95%CI):1.64(1.10,2.40)]. However, the association of serum-free kynurenine with all-cause mortality was no more significant after adjustment on serum-free tryptophan [311 events, HR(95%CI):1.12(0.90, 1.40)].

Conclusions

Our findings imply that serum-free kynurenine, independently of other cardiovascular risk factors (including eGFR), is associated with fatal or nonfatal cardiovascular outcomes, particularly non-atheromatous cardiovascular events; in patients with CKD. Strategies to reduce serum kynurenine levels should be evaluated in further studies.

The Gut-Organ Axis within the Human Body: Gut Dysbiosis and the Role of Prebiotics

The human gut microbiota (GM) is a complex microbial ecosystem that colonises the gastrointestinal tract (GIT) and is comprised of bacteria, viruses, fungi, and protozoa. The GM has a symbiotic relationship with its host that is fundamental for body homeostasis. The GM is not limited to the scope of the GIT, but there are bidirectional interactions between the GM and other organs, highlighting the concept of the "gut-organ axis". Any deviation from the normal composition of the GM, termed "microbial dysbiosis", is implicated in the pathogenesis of various diseases. Only a few studies have demonstrated a relationship between GM modifications and disease phenotypes, and it is still unknown whether an altered GM contributes to a disease or simply reflects its status. Restoration of the GM with probiotics and prebiotics has been postulated, but evidence for the effects of prebiotics is limited. Prebiotics are substrates that are "selectively utilized by host microorganisms, conferring a health benefit". This study highlights the bidirectional relationship between the gut and vital human organs and demonstrates the relationship between GM dysbiosis and the emergence of certain representative diseases. Finally, this article focuses on the potential of prebiotics as a target therapy to manipulate the GM and presents the gaps in the literature and research.

Effects of resveratrol on inflammation and oxidative stress induced by the uremic toxin indoxyl sulfate in Murine macrophage-like RAW 264.7

Indoxyl sulfate (IS) is a uremic toxin produced by the gut microbiota that commonly accumulates in patients with chronic kidney disease (CKD) and can be harmful. Resveratrol is a polyphenol with properties that attenuate oxidative stress and inflammation. This study aims to evaluate the effect of resveratrol against the damage caused by IS in RAW 264.7 murine macrophages. Cells were treated with 0, 250, 500 and 1000 μmol/L of IS, in the presence of 50 μmol/L of resveratrol. The mRNA and protein expressions of erythroid-related nuclear factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB) were measured using rt-PCR and Western blot analysis, respectively. Malondialdehyde (MDA) and reactive oxygen species (ROS) levels were also analyzed. As a result, it was demonstrated that resveratrol induces the activation of the Nrf2 pathway that enhances cytoprotective response. IS upregulated the NF-κB expression and downregulated the Nrf2 expression. In contrast, resveratrol treatment significantly reduced the MDA and ROS production and inhibited the IS-induced expression of NF-κB in macrophage-like RAW 264.7. In conclusion, resveratrol can mitigate inflammation and oxidative stress caused by uremic toxins produced by the gut microbiota, such as IS.

Worsening renal function in hospitalized patients with systolic heart failure: prevalence and risk factors

AIMS

Heart failure (HF) is usually associated with complications of other organs. Renal impairment is seen in a significant proportion of HF patients and is characterized by worsening renal function (WRF). WRF can be used for predicting symptom exacerbation in systolic HF. This study aimed to determine the prevalence and risk factors of WRF among hospitalized patients with systolic HF.

METHODS AND RESULTS

In this cross-sectional study, data from medical records of 347 hospitalized patients diagnosed with HFrEF from 2019 to 2020, admitted to Tabriz Shahid Madani Heart Hospital, who met the predefined inclusion criteria, were retrieved. Patients were divided into two groups based on the in-hospital occurrence of WRF. Laboratory tests and para-clinical findings were collected and analysed using SPSS Version 20.0. Statistical significance was accepted at a P value of <0.05. In this study, 347 hospitalized patients with HFrEF were included. The mean (standard deviation) age was 62.34 (±18.87) years. The mean (SD) length of stay was 6.34 (±4) days. According to our findings, 117 patients (33.71%) had WRF. Following multivariate analysis of potential predictors of WRF occurrence, hyponatremia, haemoglobin concentration, white blood cell count and prior diuretic use were found to be independent predictors for WRF occurrence in patients with systolic heart failure.

CONCLUSIONS

This study revealed that in patients with WRF, mortality rate and length of stay were significantly greater than those of patients without WRF. Initial clinical characteristics of HF patients who developed WRF can help physicians identify patients with a higher risk of WRF.

Serum Trimethylamine N-Oxide Level Is Positively Associated with Aortic Stiffness Measured by Carotid-Femoral Pulse Wave Velocity in Patients Undergoing Maintenance Hemodialysis

Trimethylamine N-oxide (TMAO) is a biomarker that is effective in predicting major adverse cardiovascular (CV) events. Age-related vascular problems are significantly affected by aortic stiffness (AS), which is independently linked to CV morbidity and mortality. This study aimed to determine the association between serum TMAO levels and carotid-femoral pulse wave velocity (cfPWV) in patients receiving hemodialysis (HD) therapy. In total, 115 patients with HD were enrolled in this study. The AS group included patients whose cfPWV was >10 m/s. Using high-performance liquid chromatography and mass spectrometry, the levels of serum TMAO were measured. The AS group included 42 (36.5%) patients, and compared with the non-AS group, the rates of diabetes, hypertension, older age, systolic blood pressure, serum glucose, and TMAO levels were high. In the multivariate logistic regression analysis, serum TMAO and age were independently linked with AS after correcting for the factors significantly associated with AS. Following multivariate stepwise linear regression analysis, serum TMAO in these individuals was found to be strongly correlated with cfPWV values (p < 0.001). In patients on chronic HD, serum TMAO level is an independent measure of AS and strongly correlated with cfPWV.

Biotics (Pre-, Pro-, Post-) and Uremic Toxicity: Implications, Mechanisms, and Possible Therapies

In recent years, more scientific data have pointed out the close connection between intestinal microbial community, nutritional habits, lifestyle, and the appearance of various affections located at certain anatomical systems. Gut dysbiosis enhances the formation and accumulation of specific metabolites with toxic potential that induce the appearance of kidney-associated illnesses. Intestinal microbes are involved in the degradation of food, drugs, or other ingested products that lead to the formation of various metabolites that end up in renal tissue. Over the last few years, the possibilities of modulating the gut microbiota for the biosynthesis of targeted compounds with bioactive properties for reducing the risk of chronic illness development were investigated. In this regard, the present narrative review provides an overview of the scientific literature across the last decade considering the relationship between bioactive compounds, pre-, pro-, and post-biotics, uremic toxicity, and kidney-associated affections, and the possibility of alleviating the accumulation and the negative effects of uremic toxins into the renal system.

Plasma Cell-Free DNA and Caspase-3 Levels in Patients with Chronic Kidney Disease

BACKGROUND

Cell-free plasma DNA (cfDNA) is circulating extracellular DNA arising from cell death mechanisms (apoptosis, necrosis, etc.). It is commonly existent in healthy individuals, but its ranks increase in diverse clinical circumstances, such as kidney disease, sepsis, myocardial infarction, trauma and cancer. In patients with advanced chronic kidney disease, cfDNA is connected to inflammation, and it has been associated with higher mortality. Caspase-3 plays a dominant role in apoptosis, a mechanism of programmed cell death involved in the pathogenesis and progression of chronic kidney disease (CKD). The aim of this pilot study was the evaluation of cfDNA levels and caspase-3 concentrations in patients with chronic kidney disease, in order to investigate the potential role of these molecules, deriving from inflammatory and apoptotic mechanisms, in the progression of renal damage.

METHODS

We compared cfDNA and caspase-3 levels in 25 CKD patients and in 10 healthy subjects, evaluating their levels based on CKD stage. We also explored correlations between cfDNA and caspase-3 levels in CKD patients and between cfDNA and caspase-3 levels and serum creatinine and urea in this population.

RESULTS

We observed that cfDNA and caspase-3 levels were higher in patients with CKD compared to healthy subjects, in particular in patients with advanced renal disease (CKD stage 5). A positive correlation between cfDNA and caspase-3 levels and between cfDNA and caspase-3 and creatinine and urea were also noticed.

CONCLUSIONS

Patients with chronic kidney disease show higher levels of cfDNA and caspase-3 levels compared to the control group. Based on these preliminary results, we speculated that the worsening of renal damage and the increase in uremic toxin concentration could be associated with higher levels of cfDNA and caspase-3 levels, thus reflecting the potential role of inflammation and apoptosis in the progression of CKD. Future studies should focus on the validation of these promising preliminary results.

The Gut-Peritoneum Axis in Peritoneal Dialysis and Peritoneal Fibrosis

Peritoneal fibrosis is an important cause of peritoneal dialysis (PD) discontinuation worldwide and is associated with high morbidity and mortality rate. Although the era of metagenomics has provided new insights into the interactions between the gut microbiota and fibrosis in various organs and tissues, its role in peritoneal fibrosis has rarely been discussed. This review provides a scientific rationale and points out the potential role of gut microbiota in peritoneal fibrosis. In addition, the interaction between the gut, circulatory, and peritoneal microbiota is highlighted, with an emphasis on the relationship to PD outcomes. More research is needed to elucidate the mechanisms underlying the role of gut microbiota in peritoneal fibrosis and potentially unveil new target options for the management of PD technique failure.

The Role of Dyslipidemia in Atherogenesis in Peritoneal Dialysis Patients

Background

To evaluate atherosclerotic changes in carotid arteries (CCA) in uremic patients before and after 18 months of continuous ambulatory peritoneal dialysis (CAPD) treatment, and to evaluate the impact of dyslipidemia and CAPD treatment on vascular remodeling.

Materials and Methods

We conducted a longitudinal, prospective study during 2020 and 2021 at the Clinic for Nephrology, Clinical Center University of Sarajevo. Patients with end-stage renal disease were included and were followed during 18 months of CAPD treatment. All patients were treated using commercially prepared biocompatible balanced dialysis solutions. Carotid intima-media thickness (IMT) and atherosclerotic plaques on the common carotid artery (CCA) were measured by echotomography.

Results

A total of 50 patients were included and were followed during 18 months of CAPD treatment. Lipid values in the serum of patients with CAPD were significantly lower after 18 months of CAPD treatment compared to the values before treatment, while the value of high-density lipoprotein (HDL) was significantly increased after 18 months of CAPD treatment. The values of IMT and the diameter of the CCA compared to the basal values were significantly lower (P < 0.001).

Conclusion

We demonstrated significantly lower lipid values and higher HDL levels following CAPD treatment. Correct selection of the targeted pharmacological intervention can substantially impact the regression of vascular changes in patients on peritoneal dialysis.

Proton-Pump Inhibitors and Serum Concentrations of Uremic Toxins in Patients with Chronic Kidney Disease

Use of proton-pump inhibitors (PPIs) is common in patients with chronic kidney disease (CKD). PPIs and many uremic toxins (UTs) are eliminated by the kidney's tubular organic anion transporter system. In a cross-sectional study, we sought to evaluate the association between PPI prescription and serum concentrations of various UTs. We studied a randomly selected sub-group of participants in the CKD-REIN cohort (adult patients with a confirmed diagnosis of CKD and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²) with available frozen samples collected at baseline. PPI prescription was recorded at baseline. Serum concentrations of 10 UTs were measured using a validated liquid chromatography tandem mass spectrometry technique. Multiple linear regression was performed, with the log UT concentration as the dependent variable. Of the 680 included patients (median age: 68 years; median eGFR: 32 mL/min/1.73 m²), 31% had PPI prescriptions at baseline. Patients using PPIs had higher levels of certain UTs in comparison to other patients, including total and free indoxyl sulfate (IS), total and free p-cresylsulfate, total and free p-cresylglucuronide (PCG), phenylacetylglutamine (PAG), free kynurenine, and free hippuric acid. After adjustment for baseline co-morbidities, number of co-prescribed drugs, and laboratory data, including eGFR, associations between PPI prescription and elevated serum concentrations of free and total IS, free and total PCG, and PAG remained significant. Our results indicate that PPI prescription is independently associated with serum UT retention. These findings are interesting to better understand the factors that may modulate serum UT concentration in CKD patients, however, they will need to be confirmed by longitudinal studies.

Zebrafish as a Model of Cardiac Pathology and Toxicity: Spotlight on Uremic Toxins

Chronic kidney disease (CKD) is an increasing health care problem. About 10% of the general population is affected by CKD, representing the sixth cause of death in the world. Cardiovascular events are the main mortality cause in CKD, with a cardiovascular risk 10 times higher in these patients than the rate observed in healthy subjects. The gradual decline of the kidney leads to the accumulation of uremic solutes with a negative effect on every organ, especially on the cardiovascular system. Mammalian models, sharing structural and functional similarities with humans, have been widely used to study cardiovascular disease mechanisms and test new therapies, but many of them are rather expensive and difficult to manipulate. Over the last few decades, zebrafish has become a powerful non-mammalian model to study alterations associated with human disease. The high conservation of gene function, low cost, small size, rapid growth, and easiness of genetic manipulation are just some of the features of this experimental model. More specifically, embryonic cardiac development and physiological responses to exposure to numerous toxin substances are similar to those observed in mammals, making zebrafish an ideal model to study cardiac development, toxicity, and cardiovascular disease.

Hypomagnesemia as a Risk Factor and Accelerator for Vascular Aging in Diabetes Mellitus and Chronic Kidney Disease

The age-old axiom that one is as old as his or her vessels are, calls for ongoing critical re-examination of modifiable risk factors of accelerated vascular ageing in chronic kidney diseases. Attempts to modulate vascular risk with cholesterol-lowering agents have largely failed in advanced chronic kidney disease (CKD). In addition to nitrogen waste products, many pathological biochemical processes also play a role in vascular calcification in chronic kidney damage. Magnesium, a cation vital for the body, may substantially reduce cardiovascular diseases' risk and progression. This narrative review aimed to address the relationship between hypomagnesemia and vascular calcification, which promotes further cardiovascular complications in diabetes, aging, and CKD. Articles with predefined keywords were searched for in the PubMed and Google Scholar databases with specific inclusion and exclusion criteria. We hypothesized that a decrease in serum magnesium levels contributes to increased vascular calcification and thereby increases cardiovascular mortality. In summary, based on existing evidence in the literature, it appears that simple and inexpensive oral magnesium supplementation may reduce the cardiovascular mortality of patients who are already severely affected by such diseases; in this context, the concept of 'normal' vs. 'ideal' serum magnesium levels should be carefully re-examined.

Paradoxical reduction of plasma lipids and atherosclerosis in mice with adenine-induced chronic kidney disease and hypercholesterolemia

Background

Atherosclerotic cardiovascular disease is prevalent among patients with chronic kidney disease (CKD). In this study, we initially aimed to test whether vascular calcification associated with CKD can worsen atherosclerosis. However, a paradoxical finding emerged from attempting to test this hypothesis in a mouse model of adenine-induced CKD.

Methods

We combined adenine-induced CKD and diet-induced atherosclerosis in mice with a mutation in the low-density lipoprotein receptor gene. In the first study, mice were co-treated with 0.2% adenine in a western diet for 8 weeks to induce CKD and atherosclerosis simultaneously. In the second study, mice were pre-treated with adenine in a regular diet for 8 weeks, followed by a western diet for another 8 weeks.

Results

Co-treatment with adenine and a western diet resulted in a reduction of plasma triglycerides and cholesterol, liver lipid contents, and atherosclerosis in co-treated mice when compared with the western-only group, despite a fully penetrant CKD phenotype developed in response to adenine. In the two-step model, renal tubulointerstitial damage and polyuria persisted after the discontinuation of adenine in the adenine-pre-treated mice. The mice, however, had similar plasma triglycerides, cholesterol, liver lipid contents, and aortic root atherosclerosis after being fed a western diet, irrespective of adenine pre-treatment. Unexpectedly, adenine pre-treated mice consumed twice the calories from the diet as those not pre-treated without showing an increase in body weight.

Conclusion

The adenine-induced CKD model does not recapitulate accelerated atherosclerosis, limiting its use in pre-clinical studies. The results indicate that excessive adenine intake impacts lipid metabolism.

3-Carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) induces cell death through ferroptosis and acts as a trigger of apoptosis in kidney cells

Ferroptosis is a cell death mechanism characterized by intracellular iron accumulation and lipid peroxidation. Effects of uremic toxins on ferroptosis in the kidney are not well understood. We investigated whether protein-bound uremic toxins induce ferroptosis, resulting in cell death, using the bilateral ureteral obstruction (BUO) mouse model and kidney cells. In BUO mice, we observed elevated lipid peroxidation, increased iron concentration, and decreased glutathione peroxidase 4 (GPX4) expression. Levels of transferrin receptor 1 and system Xc-, which are involved in iron transport and storage, were also elevated, while those of ferritin heavy and light chains (FHC and FLC) were reduced. Treatment of HK-2 and NRK49F kidney cells with CMPF decreased GSH levels and the expression of GPX4, FHC, and FLC, and increased levels of ROS, lipid peroxidation, and intracellular iron concentration. CMPF-induced and erastin-induced decreases in GPX4 levels and increases in Bax and cytochrome C levels were counteracted by ferrostatin-1 pretreatment. However, GPX4 mRNA levels, protein abundance, or promoter activity were not restored by Z-VAD-FMK, a multi-caspase inhibitor. These results suggest that ferroptosis induced by CMPF treatment induces apoptosis, and inhibition of ferroptosis reduces apoptosis, suggesting that ferroptosis plays a role in triggering cell death by apoptosis.

Evolving Concepts on Inflammatory Biomarkers and Malnutrition in Chronic Kidney Disease

While patient care, kidney replacement therapy, and transplantation techniques for chronic kidney disease (CKD) have continued to progress, the incidence of malnutrition disorders in CKD appears to have remained unchanged over time. However, there is now a better understanding of the underlying pathophysiology according to the disease background, disease stage, and the treatment received. In CKD patients, the increased production of proinflammatory cytokines and oxidative stress lead to a proinflammatory milieu that is at least partially responsible for the increased morbidity and mortality in this patient population. New insights into the pathogenic role of innate immunity and the proinflammatory cytokine profile, characterized, for instance, by higher levels of IL-6 and TNF-α, explain some of the clinical and laboratory abnormalities observed in these patients. In this article, we will explore currently available nutritional-inflammatory biomarkers in distinct CKD populations (hemodialysis, peritoneal dialysis, transplantation) with a view to evaluating their efficacy as predictors of malnutrition and their involvement in the common proinflammatory process. Although there is a direct relationship between inflammatory-nutritional status, signs and symptoms [e.g., protein-energy wasting (PEW), anorexia], and comorbidities (e.g., atheromatosis, atherosclerosis), we are in need of clearly standardized markers for nutritional-inflammatory assessment to improve their performance and design appropriate bidirectional interventions.

PCSK9 and Other Metabolic Targets to Counteract Ischemia/Reperfusion Injury in Acute Myocardial Infarction and Visceral Vascular Surgery

Ischemia/reperfusion (I/R) injury complicates both unpredictable events (myocardial infarction and stroke) as well as surgically-induced ones when transient clampage of major vessels is needed. Although the main cause of damage is attributed to mitochondrial dysfunction and oxidative stress, the use of antioxidant compounds for protection gave poor results when challenged in clinics. More recently, there is an assumption that, in humans, profound metabolic changes may prevail in driving I/R injury. In the present work, we narrowed the field of search to I/R injury in the heart/brain/kidney axis in acute myocardial infarction, major vascular surgery, and to the current practice of protection in both settings; then, to help the definition of novel strategies to be translated clinically, the most promising metabolic targets with their modulatory compounds—when available—and new preclinical strategies against I/R injury are described. The consideration arisen from the broad range of studies we have reviewed will help to define novel therapeutic approaches to ensure mitochondrial protection, when I/R events are predictable, and to cope with I/R injury, when it occurs unexpectedly.

Changes in Cardiac Function During the Development of Uremic Cardiomyopathy and the Effect of Salvianolic Acid B Administration in a Rat Model

Background

Uremic cardiomyopathy (UC), the main cause of death in progressive chronic kidney disease (CKD), is characterized by diastolic dysfunction. Intraventricular pressure gradients (IVPG) derived from color m-mode echocardiography (CMME) and two-dimensional speckle tracking echocardiography (2DSTE) were established as novel echocardiographic approaches for non-invasive and repeatable assessment of cardiac function. Previously, salvianolic acid B (Sal B) showed the potential to alleviate concentric LV hypertrophy in the pressure overload model. The purpose of this study was to evaluate the changes in cardiac function in UC and assess the efficacy of Sal B therapy using IVPG and 2DSTE techniques.

Materials and Methods

Twenty-four rats underwent subtotal nephrectomy to produce progressive renal failure and were allocated equally into UC (n = 12) and Sal B-UC (n = 12) groups and monitored for 8 weeks. A sham-operated group was also included in this study (n = 12). Sal B was injected from weeks 4 to 8 in the Sal B-UC group. Conventional echocardiography, 2DSTE, and CMME were performed every 2 weeks post-operation, concomitantly with an evaluation of renal function. Histopathological and immunohistochemistry analyses were carried out to confirm the echocardiography findings.

Results

Renal failure and myocardial dysfunction were confirmed in the UC group from weeks 2 through 8. Eccentric and concentric hypertrophy was observed in the UC group, while the Sal B-UC group showed only eccentric hypertrophy. IVPG analysis did not reveal any significant differences between the groups. Edema, inflammation, fibrosis, and immunohistochemical expression of CD3 infiltration were higher in the UC group compared with sham and Sal B-UC groups.

Conclusion

2DSTE and IVPG explored the pathophysiology during the development of UC and indicated the incidence of myocardial dysfunction before ventricular morphological changes without intracardiac flow changes. This study confirmed increased ventricular stiffness and fibrosis in UC rats which was potentially treated by Sal B via decreasing edema, inflammation, and fibrosis.

Short-Chain Fatty Acids in Chronic Kidney Disease: Focus on Inflammation and Oxidative Stress Regulation

Chronic Kidney Disease (CKD) is a debilitating disease associated with several secondary complications that increase comorbidity and mortality. In patients with CKD, there is a significant qualitative and quantitative alteration in the gut microbiota, which, consequently, also leads to reduced production of beneficial bacterial metabolites, such as short-chain fatty acids. Evidence supports the beneficial effects of short-chain fatty acids in modulating inflammation and oxidative stress, which are implicated in CKD pathogenesis and progression. Therefore, this review will provide an overview of the current knowledge, based on pre-clinical and clinical evidence, on the effect of SCFAs on CKD-associated inflammation and oxidative stress.