Natália A. Borges

Is there interaction between gut microbial profile and cardiovascular risk in chronic kidney disease patients

AIM To evaluate the gut microbial profile in chronic kidney disease (CKD) patients and evaluate the possible relationship with inflammation and cardiovascular risk. PATIENTS & METHODS Markers inflammation plasma and bacterial community profile (denaturing gradient gel electrophoresis) were analyzed. RESULTS The average number of bands was not different in healthy individuals and CKD patients. The number of bands was negatively associated with plasma levels of VCAM-1 in patients. Flavobacteriaceae bacterium and Listeria monocytogenes were found in patients and Lachnospiraceae bacterium and Butyrivibrio crossotus in healthy individuals. CONCLUSION Although CKD patients did not present altered gut microbial profile, the sequencing of bands suggested a different microbiota between groups. The result suggests a possible relationship between gut microbiota and cardiovascular risk in CKD patients.

Resistant starch for modulation of gut microbiota: Promising adjuvant therapy for chronic kidney disease patients?

The gut microbiota has been extensively studied in all health science fields because its imbalance is linked to many disorders, such as inflammation and oxidative stress, thereby contributing to cardiovascular disease, obesity, diabetes and chronic kidney disease (CKD) complications. Novel therapeutic strategies that aim to reduce the complications caused by this imbalance have increased in recent years. Studies have shown that prebiotic supplementation can beneficially modulate the gut microbiota in CKD patients. Prebiotics consist of non-digestible dietary soluble fiber, which acts as a substrate for the gut microbiota. Resistant starch (RS) is a type of dietary fiber that can reach the large bowel and act as a substrate for microbial fermentation; for these reasons, it has been considered to be a prebiotic. Few studies have analyzed the effects of RS on the gut microbiota in CKD patients. This review discusses recent information about RS and the potential role of the gut microbiota, with a particular emphasis on CKD patients.

Red meat intake in chronic kidney disease patients: Two sides of the coin

Red meat is an important dietary source of high biological value protein and micronutrients such as vitamins, iron, and zinc that exert many beneficial functions. However, high consumption of animal protein sources, especially red meat, results in an increased intake of saturated fat, cholesterol, iron, and salt, as well as an excessive acid load. Red meat intake may lead to an elevated production of uremic toxins by the gut microbiota, such as trimethylamine n-oxide (TMAO), indoxyl sulfate, and p-cresyl sulfate. These uremic toxins are associated with increased risk for cardiovascular (CV) mortality. Limiting the intake of red meat in patients with chronic kidney disease (CKD) thus may be a good strategy to reduce CV risk, and may slow the progression of kidney disease. In the present review, we discuss the role of red meat in the diet of patients with CKD. Additionally, we report on a pilot study that focused on the effect of a low-protein diet on TMAO plasma levels in nondialysis CKD patients.

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.

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.

Is there a relationship between tryptophan dietary intake and plasma levels of indoxyl sulfate in chronic kidney disease patients on hemodialysis

INTRODUCTION Gut microbiota is involved in generation of uremic toxins in chronic kidney disease (CKD) patients on hemodialysis (HD), like indoxyl sulfate (IS) that is originated from tryptophan amino acid fermentation. OBJECTIVE To evaluate the tryptophan intake by chronic renal failure patients on HD and its possible relationship with IS plasma levels. METHODS Participated of the study 46 patients with CKD on HD regular program (56.5% men; 52.7 ± 10.3 years; 63 (32.2-118.2) months on HD; BMI 25.6 ± 4.9 kg/m2). The tryptophan intake was evaluated by a 24-hours dietary recall (R-24h) performed on 3 different days. Routine biochemical tests and anthropometric measurements were evaluated. IS plasma levels were determined by High Performance Liquid Chromatography (HPLC) with fluorescent detection and the interleukin-6 (IL-6) plasma levels by immunoenzymatic method (ELISA, Enzyme Linked Immunosorbent Assay). RESULTS The average of tryptophan intake was according to recommendation, but IS plasma levels (35.0 ± 11.9 mg/L) were elevated, however according to the EUTox values for uremic individuals. There was no correlation between the tryptophan intake and IS plasma levels. However, there was positive correlation between protein intake and tryptophan and variables used to evaluate lean body mass, and moreover, IS levels were positively associated with IL-6 (r = 0.6: p = 0.01). CONCLUSION The present study suggests that tryptophan dietary intake may not be a determinant factor to IS levels. However, it suggests that gut microbiota may play an important role in systemic inflammation in patients with CKD.

Effects of acute resistance exercise on acyl-ghrelin and obestatin levels in hemodialysis patients: a pilot study.

Abstract Chronic physical exercises may be beneficial to modulate appetite hormones as acyl-ghrelin (orexigenic) and obestatin (anorexigenic) in chronic kidney disease (CKD) patients; however, there are no data about the effects of acute exercises on these hormones. Thus, the aim of the present study was to assess the effect of acute resistance exercise on appetite hormones (acyl-ghrelin and obestatin) of patients undergoing hemodialysis (HD). Twenty-five patients (44.7 ± 12.9 years, 68% women) on regular HD program were enrolled into two groups, 16 patients performed exercises and 9 patients comprised the control group. The patients performed the exercises in both lower limbs with ankle-cuffs and elastic bands, 30 min after the initiation of hemodialysis session. Blood samples of both the groups were drawn in the morning before and after 30 min with exercise session (exercise group) and, before and after the same time without exercise (control group). Acyl-ghrelin and obestatin plasma levels were measured using an enzyme immunometric assay. Acyl-ghrelin plasma levels did not change in both the groups. However, when stratified by gender the acyl-ghrelin increased significantly right after exercise in men [32.1 pg/mL (25.6–41.2) to 46.0 pg/mL (39.0–59.5)] (p = 0.04). Obestatin plasma levels reduced after a single bout of exercise and changes remained significantly when the sample was stratified by gender. There was no change in obestatin plasma levels in control group. A single bout of resistance exercise seems to modulate the levels of appetite hormones in HD patients.

Acyl-Ghrelin and Obestatin Plasma Levels in Different Stages of Chronic Kidney Disease

OBJECTIVE This study assessed acyl-ghrelin and obestatin plasma levels in nondialysis chronic kidney disease (CKD) and hemodialysis (HD) patients compared with healthy volunteers. DESIGN This was a cross-sectional study conducted at Renal Vida Clinic (Rio de Janeiro, Brazil) and Renal Nutrition Ambulatory (Niterói, Brazil). SUBJECTS Sixty-four subjects were studied: 29 HD patients (55.4 ± 10.5 years, body mass index [BMI], 24.4 ± 3.9 kg/m(2), 17 men); 19 nondialysis patients (59.8 ± 7.5 years, BMI, 26.3 ± 4.8 kg/m(2), glomerular filtration rate, 28.8 ± 10.5 mL/minute/1.73 m(2), 5 men), and 16 healthy volunteers (53.8 ± 5.4 years, BMI, 24.6 ± 2.7 kg/m(2), 7 men). MAIN OUTCOME MEASURE Acyl-ghrelin and obestatin were assessed using enzyme immunometric assays. Body weight, height, waist circumference (WC), and skinfold were measurement, and body fat percentage, arm muscle area, BMI, and conicity index were calculated. The average daily intake of calories and protein were estimated using a 3-day, 24-hour dietary recall, and the appetite was assessed by the first question of the Hemodialysis Study Appetite Questionnaire. RESULTS The highest serum acyl-ghrelin (34.1 ± 13.0 pg/mL) and acyl-ghrelin/obestatin ratio (34.0 [6.7-90.2]) were found in nondialysis CKD patients who also presented with the lowest obestatin levels (0.8 [0.30-2.7] ng/mL) when compared with HD patients and healthy volunteers. HD patients presented the highest obestatin plasma levels (3.0 [2.7-3.4] ng/mL) and the lowest acyl-ghrelin/obestatin ratio (P < .05). Obestatin levels inversely correlated with WC (r = -0.6, P < .04) and BMI (r = -0.56, P < .04) in healthy volunteers. CONCLUSION Although no correlation was found for appetite and food intake with acyl-ghrelin and obestatin in CKD patients, HD patients have the most important alteration of acyl-ghrelin and obestatin plasma levels and had a more impaired nutritional status than nondialysis CKD individuals.

Fructose intake: is there an association with uric acid levels in nondialysis-dependent chronic kidney disease patients?

INTRODUCTION Fructose intake has increased dramatically in consequence of the consumption of fructose-based sweetened foods and beverages. Research suggests that high fructose intake has a strong association with uric acid (UA) levels and worse prognosis of chronic kidney disease (CKD). OBJECTIVE The aim of this study was to investigate the influence of fructose intake on plasma UA levels in nondialysis- dependent CKD patients. METHODS Fifty-two patients on stages 3-5 (64.2 ± 9.6 years, 24 men, glomerular filtration rate of 30.5 ± 10.3 ml/ min) were divided into two groups: high fructose intake (>50 g/d, n=29, 61.7 ± 9.3 years) and low fructose intake (

The value of the Brazilian açai fruit as a therapeutic nutritional strategy for chronic kidney disease patients

Açai (Euterpe oleracea Mart.) fruit from the Amazon region in Brazil contains bioactive compounds such as α-tocopherol, anthocyanins (cyanidin 3-glycoside and cyanidin 3-rutinoside), and other flavonoids with antioxidant and anti-inflammatory properties. Moreover, the prebiotic activity of anthocyanins in modulating the composition of gut microbiota has emerged as an additional mechanism by which anthocyanins exert health-promoting effects. Açai consumption may be a nutritional therapeutic strategy for chronic kidney disease (CKD) patients since these patients present with oxidative stress, inflammation, and dysbiosis. However, the ability of açai to modulate these conditions has not been studied in CKD, and this review presents recent information about açai and its possible therapeutic effects in CKD.