Jaboticaba ( Plinia cauliflora ), a typical Brazilian fruit, as a strategy to modulate inflammation, oxidative stress, and gut dysbiosis in patients with chronic kidney disease: Study protocol for a Randomized, Controlled Dietary Crossover Trial

Jaboticaba, Plinia cauliflora [Mart.] Kausel ( Myrtaceae ) is a native Brazilian fruit high in bioactive compounds with potent antioxidant and anti-inflammatory properties. We present the first protocol (randomized crossover with a washout period) for a clinical trial investigating the effects of consuming jaboticaba peel extract on inflammation, oxidative stress, and gut dysbiosis in patients with chronic kidney disease (CKD) undergoing hemodialysis. Thirty eligible patients will be randomly assigned to the intervention group (3.3 g/day of jaboticaba peel extract, providing 650 mg/day of phenolic compounds) or to the placebo group (corn starch). The total daily dose will be administered as four capsules, divided into two doses per day, for two months. Following the washout period (two months), patients will continue the supplementation in a crossover design for the same duration. Blood and fecal samples, food intake data, and anthropometric measurements will be evaluated. Inflammatory markers and antioxidant enzymes will be assessed using RT-protein chain reaction, cytokine plasma levels will be measured by Luminex, and uremic toxin plasma levels will be analyzed using high-performance liquid chromatography. The fecal microbiome will be evaluated through high-throughput sequencing of the 16S rRNA gene amplicons. Conducting a rigorously designed trial using jaboticaba will provide essential information and generate new evidence to support nutritional strategies that utilize typical Brazilian fruits for patients with CKD. This trial was registered at ClinicalTrials.gov (NCT06394531).