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.

Tocotrienols, isomers of vitamin E, may provide an effective nutritional strategy to mitigate common cardiovascular risks such as dyslipidemia, inflammation, and oxidative stress in patients with chronic kidney disease (CKD). This double‐blind, placebo‐controlled, randomized clinical trial aimed to evaluate the effects of a tocotrienol‐rich fraction (TRF) supplementation (300 mg/day) on oxidative stress and inflammatory markers, including transcription factors in nondialysis (ND) and hemodialysis (HD) CKD patients for three months. Interleukin‐6, tumor necrosis factor‐ α (IL‐6 and TNF‐ α ), C‐reactive protein (CRP), lipid peroxidation, biochemical parameters, and transcription factors such as NRF2 and NF‐ κ B mRNA expression were evaluated. Seventeen HD patients (9 in the placebo group, 8 in the TRF group) and 16 ND CKD patients (8 in the placebo group and 8 in the TRF group) completed the study. In HD patients, significant reductions were observed in LDL cholesterol ( p = 0.04) and total plasma cholesterol levels ( p = 0.01) after TRF intervention. CRP serum levels decreased significantly in ND CKD patients ( p = 0.05) after TRF supplementation. Transcription factors NRF2 and NF‐ κ B mRNA expressions remained unaltered in both groups. This study suggests that TRF supplementation may mitigate dyslipidemia and inflammation, factors involved with increased cardiovascular risk, in CKD patients, with variations in efficacy between HD and ND patients. Trial Registration: ClinicalTrials.gov identifier: NCT04900532

Background. Growing evidence suggests that bioactive compounds in berry fruits may mitigate inflammation in patients with chronic kidney disease (CKD). Objectives. To evaluate cranberry (Vaccinium macrocarpon) supplementation effects on modulation of transcription factors involved in inflammation and oxidative stress in nondialysis (stages 3 and 4) patients with CKD. Design/Participants. A randomized, double-blind, placebo-controlled study was performed with 30 patients to receive capsules containing cranberry extract (1000 mg/day) or placebo (1000 mg/day of corn starch) for two months. Measurements. The mRNA expression of nuclear factor-erythroid 2-related factor-2 (Nrf2) and nuclear factor-kB (NF-kB) was evaluated in peripheral blood mononuclear cells (PBMCs) by quantitative real-time polymerase chain reaction. Thiobarbituric acid reactive substances (TBARS) were measured in the plasma to assess oxidative stress. Interleukin-6 (IL-6) plasma levels were assessed by enzyme-linked immunosorbent assay and C-reactive protein (CRP) by immunoturbidimetric method. Results. Twenty-five patients completed the study: 12 in the cranberry group (56.7 ± 7.5 years and body mass index (BMI) of 29.6 ± 5.5 kg/m²) and 13 in the placebo group (58.8 ± 5.1 years and BMI 29.8 ± 5.4 kg/m²). There were no differences in NF-kB or Nrf2 mRNA expressions ( and ) or TBARS, CRP, and IL-6 plasma levels after cranberry supplementation. Conclusions. The cranberry extract administration (1000 mg/day) did not affect Nrf2 and NF-kB mRNA expression, oxidative stress, or inflammatory markers levels in nondialysis CKD patients. This trial is registered with NCT04377919.