Cinnamon: an aromatic condiment applicable to chronic kidney disease.

Cinnamon, a member of the Lauraceae family, has been widely used as a spice and traditional herbal medicine for centuries and has shown beneficial effects in cardiovascular disease, obesity, and diabetes. However, its effectiveness as a therapeutic intervention for chronic kidney disease (CKD) remains unproven. The bioactive compounds within cinnamon, such as cinnamaldehyde, cinnamic acid, and cinnamate, can mitigate oxidative stress, inflammation, hyperglycemia, gut dysbiosis, and dyslipidemia, which are common complications in patients with CKD. In this narrative review, we assess the mechanisms by which cinnamon may alleviate complications observed in CKD and the possible role of this spice as an additional nutritional strategy for this patient group.

Resistant Starch Type-2 Supplementation Does Not Decrease Trimethylamine N-Oxide (TMAO) Plasma Level in Hemodialysis Patients.

Dysbiosis is recognized as a new cardiovascular disease (CVD) risk factor in hemodialysis (HD) patients because it is linked to increased generation in the gut of uremic toxins such as trimethylamine N-Oxide (TMAO) from dietary precursors (choline, betaine, or L-carnitine). Nutritional strategies have been proposed to modulate the gut microbiota and reduce the production of these toxins. This study aimed to evaluate the effect of amylose-resistant starch (RS) supplementation on TMAO plasma levels in HD patients.We conducted a randomized, double-blind, placebo-controlled trial (NCT02706808) with patients undergoing HD enrolled in a previous pilot study. The participants were allocated to RS or placebo groups to receive 16 g/d of RS or placebo for 4 weeks. Plasma TMAO, choline, and betaine levels were measured with LC-MS/MS. Fecal microbiome composition was evaluated by 16S ribosomal RNA sequencing, followed by a search for TMA-associated taxa. Anthropometric, routine biochemical parameters, and food intake were evaluated.Twenty-five participants finished the study, 13 in the RS group, and 12 in the placebo group. RS supplementation did not reduce TMAO plasma levels. Moreover, no significant alterations were observed in choline, betaine, anthropometric, biochemical parameters, or food intake in both groups. Likewise, RS was not found to exert any influence on the proportion of potential TMA-producing bacterial taxa in fecal matter.RS supplementation did not influence plasma TMAO, choline, betaine, or fecal taxa potentially linked to TMAO. Thus, RS does not seem to modify the TMA-associated bacterial taxa, precursors of TMAO.Supplemental data for this article is available online at https://doi.org/10.1080/07315724.2021.1967814 .

Resistant starch supplementation effects on plasma indole 3-acetic acid and aryl hydrocarbon receptor mRNA expression in hemodialysis patients: Randomized, double blind and controlled clinical trial / Efeitos da suplementação de amido resistente no ácido indol-3-acético plasmático e na expressão do mRNA do receptor aril-hidrocarboneto em pacientes em hemodiálise: ensaio clínico randomizado, duplo-cego e controlado

ABSTRACT Introduction: Gut microbiota imbalance is linked to high uremic toxins production such as indole-3-acetic acid (IAA) in chronic kidney disease patients. This toxin can activate the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor involved with inflammation. Strategies to restore gut microbiota balance can be associated with reduced production of IAA and its deleterious effects. This study aimed to evaluate prebiotic resistant starch (RS) supplementation effects on IAA plasma levels and AhR mRNA expression in CKD patients on hemodialysis (HD). Methods: This randomized, double-blind and placebo-controlled clinical trial evaluated forty-two stable HD patients allocated in RS (n=22) or placebo (n=20) groups. Patients received, alternately, cookies and sachets containing 16 g/day of RS (Hi-Maize 260®) or manioc flour for four weeks. Fasting pre-dialysis blood samples were collected and IAA plasma levels measured by high performance liquid chromatography. Peripheral blood mononuclear cells were isolated and processed for AhR and nuclear factor kappa B (NF-κB) mRNA expression analyzes by quantitative real-time PCR. Anthropometric and biochemical parameters, as well as food intake were also evaluated. Results: Thirty-one patients completed the study, 15 in the RS group and 16 in the placebo group. Although there was no significant alteration in IAA plasma levels, neither in AhR mRNA expression and NF-κB mRNA expression after RS supplementation, a positive correlation (r=0.48; p=0.03) was observed between IAA plasma levels and AhR expression at baseline. Conclusion: Even though prebiotic RS supplementation did not influence IAA levels or AhR expression, their positive association reinforces a possible interaction between them.

RESUMO Introdução: O desequilíbrio da microbiota intestinal associa-se à alta produção de toxinas urêmicas tais como ácido indol-3-acético (AIA), em renais crônicos. Essa toxina ativa o receptor aril hidrocarboneto (AhR) - fator de transcrição ativado por ligante, na inflamação. Restaurar o equilíbrio da microbiota intestinal associa-se à produção reduzida de AIA e efeitos deletérios. Avaliamos os efeitos da suplementação de amido resistente prebiótico (AR) sobre AIA sérico e expressão de AhR mRNA em renais crônicos em HD. Métodos: Estudo clínico randomizado, duplo-cego, controlado por placebo, com 42 pacientes em HD, nos grupos AR (n = 22) ou placebo (n = 20). Os pacientes receberam, alternadamente, biscoitos e sachês com 16 g/dia de AR ou polvilho - 4 semanas. Coletamos amostras de sangue em jejum pré-diálise e medimos níveis séricos de AIA por cromatografia líquida de alta eficiência. Isolamos e processamos as células mononucleares do sangue periférico para avaliar expressão AhR mRNA e NF-κB por PCR quantitativo em tempo real. Avaliamos parâmetros antropométricos, bioquímicos e ingestão alimentar. Resultados: 31 pacientes, 15 AR e 16 no placebo. Apesar de não apresentarem alteração significativa nos níveis de AIA, nas expressões de AhR ou NF-κB mRNA pós- suplementação com AR, foi verificada uma correlação positiva (r = 0,48; p = 0,03) entre AIA sérico e expressão de AhR na linha basal. Conclusão: Embora a suplementação com o prebiótico de AR não tenha influenciado os níveis de AIA ou a expressão de AhR, sua associação positiva reforça possível interação entre eles.

Resistant starch supplementation effects on plasma indole 3-acetic acid and aryl hydrocarbon receptor mRNA expression in hemodialysis patients: Randomized, double blind and controlled clinical trial.

INTRODUCTION: Gut microbiota imbalance is linked to high uremic toxins production such as indole-3-acetic acid (IAA) in chronic kidney disease patients. This toxin can activate the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor involved with inflammation. Strategies to restore gut microbiota balance can be associated with reduced production of IAA and its deleterious effects. This study aimed to evaluate prebiotic resistant starch (RS) supplementation effects on IAA plasma levels and AhR mRNA expression in CKD patients on hemodialysis (HD). METHODS: This randomized, double-blind and placebo-controlled clinical trial evaluated forty-two stable HD patients allocated in RS (n=22) or placebo (n=20) groups. Patients received, alternately, cookies and sachets containing 16 g/day of RS (Hi-Maize 260®) or manioc flour for four weeks. Fasting pre-dialysis blood samples were collected and IAA plasma levels measured by high performance liquid chromatography. Peripheral blood mononuclear cells were isolated and processed for AhR and nuclear factor kappa B (NF-κB) mRNA expression analyzes by quantitative real-time PCR. Anthropometric and biochemical parameters, as well as food intake were also evaluated. RESULTS: Thirty-one patients completed the study, 15 in the RS group and 16 in the placebo group. Although there was no significant alteration in IAA plasma levels, neither in AhR mRNA expression and NF-κB mRNA expression after RS supplementation, a positive correlation (r=0.48; p=0.03) was observed between IAA plasma levels and AhR expression at baseline. CONCLUSION: Even though prebiotic RS supplementation did not influence IAA levels or AhR expression, their positive association reinforces a possible interaction between them.

Resistant starch type-2 enriched cookies modulate uremic toxins and inflammation in hemodialysis patients: a randomized, double-blind, crossover and placebo-controlled trial.

BACKGROUND: The aim of this study was to evaluate the effect of resistant starch (RS) enriched cookies supplementation on mRNA expression of nuclear transcription factors (nuclear erythroid 2-related factor, Nrf2; nuclear factor kappa-B, NF-κB), involved with inflammation and on uremic toxins levels produced by the gut microbiota in hemodialysis (HD) patients. METHODS: A randomized, double-blind, placebo-controlled crossover study with 26 HD patients was conducted. The patients were assigned to either resistant starch enriched cookies (16 g of RS per day) or placebo cookies supplementation during the first four weeks. After the washout period, patients were supplemented again, in the form of a crossover, for another 4 weeks. Nrf2, NF-κB, and antioxidant enzymes mRNA expression were measured by rt-PCR and protein expression by western blotting assay from isolated peripheral blood mononuclear cells (PBMC). Oxidative stress and inflammatory biomarkers, as well as uremic toxins, were evaluated. Intention-to-treat analysis was performed, using the proc mixed procedure in SAS. RESULTS: In RS group, post-treatment mean mRNA Nrf2 expression was market increased from baseline values, associated with a high expression of NQO1 protein. Besides, IS plasma levels were reduced in the RS group. No significant difference was observed in the placebo group. CONCLUSION: Our results suggested that resistant starch enriched cookies may be a good nutritional strategy to reduce indoxyl sulfate levels derived from the gut microbiota and also attenuate the inflammation in hemodialysis patients.

Resistant starch supplementation attenuates inflammation in hemodialysis patients: a pilot study.

PURPOSE: In chronic kidney disease (CKD) patients, dysbiosis is associated with inflammation and cardiovascular risk, so many nutritional strategies are being studied to reduce these complications. Resistant starch (RS) can be considered a prebiotic that promotes many benefits, including modulation of gut microbiota which is linked to immune-modulatory effects. The aim of this study was to evaluate the effects of RS supplementation on proinflammatory cytokines in CKD patients on hemodialysis (HD). METHODS: A double-blind, placebo-controlled, randomized trial was conducted with sixteen HD patients (55.3 ± 10.05 years, body mass index (BMI) 25.9 ± 5.42 kg/m2, 56% men, time on dialysis 38.9 ± 29.23 months). They were allocated to the RS group (16 g RS/day) or placebo group (manioc flour). The serum concentration of ten cytokines and growth factors was detected through a multiparametric immunoassay based on XMap-labeled magnetic microbeads (Luminex Corp, USA) before and after 4 weeks with RS supplementation. RESULTS: After RS supplementation, there was a reduction of Regulated upon Activation, Normal T-Cell Expressed and Secreted (p < 0.001), platelet-derived growth factor (two B subunits) (p = 0.014) and interferon-inducible protein 10 (IP-10) (p = 0.027). The other parameters did not change significantly. CONCLUSION: This preliminary result indicates that RS may contribute to a desirable profile of inflammatory markers in CKD patients.

Dietary Components That May Influence the Disturbed Gut Microbiota in Chronic Kidney Disease.

Gut microbiota imbalance is common in patients with chronic kidney disease (CKD) and associates with factors such as increased circulating levels of gut-derived uremic toxins, inflammation, and oxidative stress, which are linked to cardiovascular disease and increased morbimortality. Different nutritional strategies have been proposed to modulate gut microbiota, and could potentially be used to reduce dysbiosis in CKD. Nutrients like proteins, fibers, probiotics, and synbiotics are important determinants of the composition of gut microbiota and specific bioactive compounds such as polyphenols present in nuts, berries. and fruits, and curcumin, may also play a key role in this regard. However, so far, there are few studies on dietary components influencing the gut microbiota in CKD, and it is therefore not possible to conclude which nutrients should be prioritized in the diet of patients with CKD. In this review, we discuss some nutrients, diet patterns and bioactive compounds that may be involved in the modulation of gut microbiota in CKD and provide the background and rationale for studies exploring whether nutritional interventions with these dietary components could be used to alleviate the gut dysbiosis in patients with CKD.

A possible link between polyunsaturated fatty acids and uremic toxins from the gut microbiota in hemodialysis patients: A hypothesis.

INTRODUCTION: Indoxyl sulfate (IS) and p-cresyl sulfate (p-CS) are albumin-bound uremic toxins that are difficult to remove by hemodialysis (HD). Human serum albumin (HSA) carries several compounds, including fatty acids that can bind to site II of HSA and represent competing ligands for uremic toxins. The aim of this study was to investigate the association between fatty acids and uremic toxin plasma levels in patients undergoing HD. METHODS: Thirty-three HD patients (51.5% male, 54.9 ± 10.2 years old, 44.63 ± 28.4 months on HD, albumin level of 3.8 ± 0.3 g/dL) were evaluated. The erythrocyte fatty acid content (saturated fatty acid [SFA], monounsaturated fatty acid [MUFA], and polyunsaturated fatty acid [PUFA]) was measured by gas chromatography, and total IS and p-CS plasma levels were measured by reversed-phase high-performance liquid chromatography. FINDINGS: The mean percentages of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) + DHA and gamma-linolenic (GLA) acid in the erythrocyte membrane were 1.35% ± 0.74%, 1.85% ± 0.79%, and 0.33% ± 0.26%, respectively. The mean levels of IS and p-CS were 19.4 ± 11.9 mg/dL and 101.5 ± 57.2 mg/dL, respectively. There was no significant association between SFA and MUFA and IS and p-CS; however, a negative correlation was found between p-CS and specific PUFAs, and the association between GLA and p-CS levels was retained after adjusting for potential confounding variables (ß = -0.49, P = 0.007). DISCUSSION: Polyunsaturated fatty acids may contribute to the decrease in p-CS uremic toxin plasma levels in patients with chronic kidney disease undergoing HD.

Methyl Donor Nutrients in Chronic Kidney Disease: Impact on the Epigenetic Landscape.

Epigenetic alterations, such as those linked to DNA methylation, may potentially provide molecular explanations for complications associated with altered gene expression in illnesses, such as chronic kidney disease (CKD). Although both DNA hypo- and hypermethylation have been observed in the uremic milieu, this remains only a single aspect of the epigenetic landscape and, thus, of any biochemical dysregulation associated with CKD. Nevertheless, the role of uremia-promoting alterations on the epigenetic landscape regulating gene expression is still a novel and scarcely studied field. Although few studies have actually reported alterations of DNA methylation via methyl donor nutrient intake, emerging evidence indicates that nutritional modification of the microbiome can affect one-carbon metabolism and the capacity to methylate the genome in CKD. In this review, we discuss the nutritional modifications that may affect one-carbon metabolism and the possible impact of methyl donor nutrients on the microbiome, CKD, and its phenotype.

Could resistant starch supplementation improve inflammatory and oxidative stress biomarkers and uremic toxins levels in hemodialysis patients? A pilot randomized controlled trial.

An imbalance of gut microbiota is considered a new cardiovascular risk factor for chronic kidney disease (CKD) patients, since it is directly associated with increased uremic toxin production, inflammation and oxidative stress. Strategies such as prebiotic supplementation have been suggested to mitigate these complications. We hypothesized that prebiotic-resistant starch could ameliorate uremic toxins levels, oxidative stress, and inflammatory states in hemodialysis (HD) patients. This pilot study evaluated 31 HD patients assigned to either resistant starch (16 g of resistant starch Hi-Maize® 260) or placebo (manioc flour) supplementation, which they received for 4 weeks on alternate days through cookies on dialysis days and powder in a sachet on non-dialysis days. Levels of interleukin (IL)-6, high-sensitive C-reactive protein, thiobarbituric acid reactive substances plasma (TBARS), protein carbonylation, indoxyl sulfate (IS) and p-cresyl sulfate were measured. Anthropometric and biochemical parameters, as well as, food intake were also evaluated. As expected, resistant starch group increased fiber intake (p > 0.01), in addition the prebiotic supplementation reduced IL-6 (p = 0.01), TBARS (p > 0.01), and IS (p > 0.01) plasma levels. No significant differences were evident in the placebo group. Prebiotic-resistant starch supplementation seems to be a promising nutritional strategy to improve inflammation, oxidative stress and to reduce IS plasma levels in CKD patients on HD.

Does high intensity exercise affects irisin plasma levels in hemodialysis patients? A pilot study.

BACKGROUND: Irisin is a recently identified exercise-induced hormone that stimulates the "browning" of the white adipose tissue, at least in mice. In chronic kidney disease (CKD) patients, irisin regulation is not fully understood, and little attention has been given to the effects of exercise on irisin levels in these patients. The purpose of this study was to assess the effects of high intensity exercise on irisin plasma levels in CKD patients under hemodialysis (HD). METHODS: Fifteen HD patients (5 men, 44.4 ± 15.1 years old) were studied and served as their own controls. High intensity (single session) intradialytic strength exercises consisted of three sets of ten repetitions with four different movements in both lower limbs during 30 minutes. Blood samples were collected on different days (exercise and non-exercise day) at exactly the same time (30 and 60 minutes after the start of dialysis session). Plasma irisin levels were measured by ELISA assay and anthropometric and biochemical parameters were evaluated. RESULTS: Irisin plasma levels were significantly reduced in both exercise day (125.0 ± 18.5 to 117.4 ± 15.0 ng/mL, p=0.02) and non-exercise day (121.5 ± 13.7 to 115.4 ± 17.2 ng/mL, p=0.02) after 60 minutes of dialysis. CONCLUSION: These data suggest that intense intradialytic strength exercise was unable to increase the circulating concentration of irisin in HD patients. Moreover, our data show that after one hour of dialysis session, irisin plasma levels may be reduced.

Does high intensity exercise affects irisin plasma levels in hemodialysis patients? A pilot study / O exercício físico de alta intensidade afeta os níveis plasmáticos de irisina em pacientes em hemodiálise? Um estudo piloto

ABSTRACT Background: Irisin is a recently identified exercise-induced hormone that stimulates the "browning" of the white adipose tissue, at least in mice. In chronic kidney disease (CKD) patients, irisin regulation is not fully understood, and little attention has been given to the effects of exercise on irisin levels in these patients. The purpose of this study was to assess the effects of high intensity exercise on irisin plasma levels in CKD patients under hemodialysis (HD). Methods: Fifteen HD patients (5 men, 44.4 ± 15.1 years old) were studied and served as their own controls. High intensity (single session) intradialytic strength exercises consisted of three sets of ten repetitions with four different movements in both lower limbs during 30 minutes. Blood samples were collected on different days (exercise and non-exercise day) at exactly the same time (30 and 60 minutes after the start of dialysis session). Plasma irisin levels were measured by ELISA assay and anthropometric and biochemical parameters were evaluated. Results: Irisin plasma levels were significantly reduced in both exercise day (125.0 ± 18.5 to 117.4 ± 15.0 ng/mL, p=0.02) and non-exercise day (121.5 ± 13.7 to 115.4 ± 17.2 ng/mL, p=0.02) after 60 minutes of dialysis. Conclusion: These data suggest that intense intradialytic strength exercise was unable to increase the circulating concentration of irisin in HD patients. Moreover, our data show that after one hour of dialysis session, irisin plasma levels may be reduced.

RESUMO História: A irisina é um hormônio induzido pelo exercício recentemente identificado que estimula o "escurecimento" do tecido adiposo branco, pelo menos em camundongos. Nos pacientes com doença renal crônica (DRC), a regulação da irisina não é totalmente compreendida, e pouca atenção tem sido dada aos efeitos do exercício sobre os níveis de irisina nesses pacientes. O objetivo deste estudo foi avaliar os efeitos do exercício de alta intensidade sobre os níveis plasmáticos de irisina em pacientes com DRC em hemodiálise (HD). Métodos: 15 pacientes em HD (5 homens, 44,4 ± 15,1 anos) foram estudados e serviram como os próprios controles. Os exercícios de resistência intradialítica de alta intensidade (sessão única) consistiram em três séries de dez repetições com quatro movimentos diferentes em ambos os membros inferiores durante 30 minutos. As amostras de sangue foram coletadas em dias diferentes (dia de exercício e dia sem exercício) exatamente no mesmo horário (30 e 60 minutos após o início da sessão de diálise). Os níveis de irisina plasmática foram medidos por ensaio ELISA e os parâmetros antropométricos e bioquímicos foram avaliados. Resultados: Os níveis plasmáticos de irisina foram significativamente reduzidos tanto nos dias de exercício (125,0 ± 18,5 a 117,4 ± 15,0 ng/mL, p=0,02) quanto nos dias sem exercício (121,5 ± 13,7 a 115,4 ± 17,2 ng / mL, p=0,02), após 60 minutos de diálise. Conclusão: esses dados sugerem que o exercício intenso de resistência intradialítica não aumentou a concentração circulante de irisina em pacientes sob HD. Além disso, nossos dados mostram que após uma hora de sessão de diálise, os níveis plasmáticos de irisina podem ser reduzidos.

Could Low-Protein Diet Modulate Nrf2 Pathway in Chronic Kidney Disease?

Oxidative stress and inflammation are common findings in chronic kidney disease (CKD) patients, and they are directly linked to clinical outcomes such as protein energy wasting and cardiovascular disease. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is the master regulator of antioxidant genes, regulating the expression of detoxifying enzymes of phase II and antioxidant responses. Furthermore, Nrf2 can also regulate anti-inflammatory cellular responses, by inhibiting nuclear factor kappa B activity (transcription factor that promotes inflammation). Therefore, modulating Nrf2 can be a new therapeutic approach to reduce inflammation and oxidative stress in CKD. Low-protein diet (LPD) prescribed for nondialysis CKD patients presents numerous benefits already well established, including reduction of inflammation and oxidative stress. However, there is no available data regarding the relationship between LPD and Nrf2 modulation in these patients. This review aims to discuss the impact, if any, of LPD on Nrf2 expression, in nondialysis CKD patients.

Short-chain fatty acids: a link between prebiotics and microbiota in chronic kidney disease.

Under physiologic conditions, the human gut microbiota performs several activities essential to the body health. In contrast, their imbalances exacerbate some actions which can promote a cascade of metabolic abnormalities, and vice versa. Numerous diseases, including chronic kidney disease, are associated with gut microbiota imbalance, and among several strategies to re-establish gut symbiosis, prebiotics seem to represent an effective nonpharmacological approach. Prebiotics fermentation by gut microbiota produce short-chain fatty acids, which improve the gut barrier integrity and function, and modulate the glucose and lipid metabolism as well as the inflammatory response and immune system. Therefore, this literature review intends to discuss the beneficial effects of prebiotics in human health through short-chain fatty acids production, with a particular interest on chronic kidney disease.

Aryl Hydrocarbon Receptor Activation in Chronic Kidney Disease: Role of Uremic Toxins.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in the expression of xenobiotic-metabolizing enzymes, inflammatory cytokines and adhesion molecules. Uremic toxins such as indoxyl sulfate and indole acetic acid are derived from tryptophan fermentation by gut microbiota; they accumulate in patients with chronic kidney disease (CKD) on haemodialysis and have recently emerged as potent ligands of AhR. Therefore, AhR can serve as a mediator in inflammation and cardiovascular diseases in these patients. This review discusses current data that support a link between AhR activation and uremic toxins from gut microbiota in CKD.

Nonpharmacologic Strategies to Modulate Nuclear Factor Erythroid 2-related Factor 2 Pathway in Chronic Kidney Disease.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor with a high sensitivity to oxidative stress, which regulates the expression of detoxifying enzymes, besides that, can also control antioxidant and anti-inflammatory cellular responses. Therefore, the modulation of this transcription factor can be a new therapeutic approach to reduce complications in chronic kidney disease (CKD) patients, like oxidative stress and inflammation, which leads to increased risk of developing cardiovascular disease, the major cause of death in these patients. Recent studies have shown that nutritional components and physical exercises can regulate the activation of Nrf2; however, very few studies were performed in CKD patients. This review provides an overview about some of the nonpharmacologic strategies that may promote the activation of Nrf2, which may have impact on the human health, particularly in CKD, by preventing oxidative stress and maintaining cellular redox homeostasis.

Could physical exercise help modulate the gut microbiota in chronic kidney disease?

Chronic kidney disease (CKD) patients have several metabolic disorders caused by chronic oxidative stress and inflammation. The imbalance of gut microbiota has been identified as a factor that may contribute to the development of these disorders, which can promote cardiovascular disease in CKD patients. Among several strategies to modulate gut microbiota, physical exercise could represent a new nonpharmacological approach. Although exercise can reduce cardiovascular risk in CKD patients through its beneficial effects on oxidative stress and inflammation, there are no available data regarding the relationship between exercise and modulation of gut microbiota in CKD patients. This review is intended to provide a brief overview of the hypothesis regarding gut microbiota modulation through physical exercise, with a particular emphasis on CKD.

Effect of acute intradialytic strength physical exercise on oxidative stress and inflammatory responses in hemodialysis patients.

BACKGROUND: Oxidative stress and inflammation are common findings in chronic kidney disease (CKD) patients, and they are directly related to the increased risk of developing cardiovascular disease, which is the major cause of death in these patients, particularly for those undergoing hemodialysis (HD). Strength physical exercise is a new therapeutic approach to reduce these complications in CKD patients. Following this, the purpose of this study was to assess the effect of acute intradialytic strength physical exercise on oxidative stress and inflammatory responses in HD patients. METHODS: Sixteen HD patients were studied (11 women; 44.4±14.6 years; body mass index 23.3±4.9 kg/m(2); 61.6±43.1 months of dialysis) and served as their own controls. Acute (single session) intradialytic physical exercise were performed at 60% of the one-repetition maximum test for three sets of 10 repetitions for four exercise categories in both lower limbs during 30 minutes. Blood samples were collected on two different days at exactly the same time (30 minutes and 60 minutes after initiating the dialysis-with and without exercise). Antioxidant enzymes activity [superoxide dismutase (SOD), catalase, and glutathione peroxidase], lipid peroxidation marker levels (malondialdehyde), and inflammatory marker levels (high-sensitivity C-reactive protein) were determined. RESULTS: SOD plasma levels were significantly reduced after acute physical exercise from 244.8±40.7 U/mL to 222.4±28.9 U/mL (P=0.03) and, by contrast, increased on the day without exercise (218.2±26.5 U/mL to 239.4±38.6 U/mL, P=0.02). There was no alteration in plasma catalase, glutathione peroxidase, malondialdehyde, or high-sensitivity C-reactive protein levels in on either day (with or without exercise). Additionally, there was no association between these markers and clinical, anthropometric, or biochemical parameters. CONCLUSION: These data suggest that acute intradialytic strength physical exercise was unable to reduce oxidative stress and inflammation, and in addition, it seems to reduce plasma SOD levels, which could exacerbate the oxidative stress in HD patients.