Background & aims: Patients with Chronic Kidney Disease (CKD) have an imbalance in the gut microbiota that can lead to increase levels of lipopolysaccharides (LPS) and uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (p-CS), and indole-3 acetic acid (IAA). Among the therapeutic options for modulating gut microbiota are the bioactive compounds such as polyphenols present in cranberry, fruit with potential antioxidant and anti-inflammatory effects. This clinical trial focuses on evaluating the effects of supplementation with a dry extract of cranberry on plasma levels of LPS and uremic toxins in non-dialysis CKD patients. Methods: It was a randomized, double-blind, placebo-controlled study. Patients were randomized into two groups: the cranberry group received 500 mg of dry cranberry extract (2 times daily), and the placebo group received 500 mg of corn starch (2 times daily) for two months. LPS plasma levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and uremic toxins (IS, p-CS, and IAA) by high-performance liquid chromatography-fluorescence detection. Anthropometric measurements and food intake using the 24-h food recall technique were also evaluated before and after the intervention. Results: Twenty-five participants completed two months of supplementation: 12 patients in the cranberry group (8 women, 56.7 +or- 7.5 years, estimated glomerular filtration rate (eGFR) of 39.2 +or- 21.9 mL/min); 13 patients in the placebo group (9 women, 58.8 +or- 5.1 years, eGFR of 39.7 +or- 12.9 mL/min). As expected, there was a negative association between glomerular filtration rate and p-CS and IS plasma levels at the baseline. No change was observed in the uremic toxins and LPS levels. Conclusion: Cranberry dry extract supplementation for two months did not reduce the LPS and uremic toxins plasma levels produced by the gut microbiota in non-dialysis CKD patients.

Polyphenol-rich cranberry extracts decrease intestinal inflammation, alter gut microbiota, and decrease intestinal permeability in obese mice, but the effect has not been investigated in adults who are obese. The purpose of this randomized double-blind, cross-over feeding study in obese (BMI = 37.4 +or- 1.2 kg/m2) but otherwise healthy adults (n = 36) 35.4 +or- 1.3 years was to determine the effects of consuming 480 mL of a high polyphenolic cranberry or control beverage daily for 2 weeks on gastrointestinal permeability, markers of inflammation and immune function, and gut microbiota. An acute aspirin challenge was administered prior to assessing intestinal permeability to determine resistance to barrier function compromise. The cranberry beverage did not affect markers of gastrointestinal permeability, inflammation, or immune function. However, fecal Faecalibacterium prausnitzii and Eggerthella lenta increased with consumption of the cranberry beverage. Data suggest that the intervention impacted bacterial communities. A longer intervention may be required to observe beneficial effects on inflammation and gastrointestinal barrier function.