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.

Simple Summary Microbes present in the large intestine of humans and companion animals produce bioactive metabolites from host-ingested food. These bioactive metabolites can influence host health. A prior study in dogs that were healthy or had chronic enteritis/gastroenteritis showed that stool quality improved when they ate food containing a fiber bundle made from fibers of pecan shells, flax seed, cranberry, citrus, and beet. In addition, eating food containing the fiber bundle resulted in the gut bacteria shifting from digesting mainly protein to digesting mainly carbohydrates. The present study tested the impact of the fiber bundle at a lower range of concentrations in dogs. Fecal levels of several bioactive metabolites with beneficial antioxidant or anti-inflammatory properties increased after dogs consumed food with the fiber bundle, though no changes in the bacteria or their functional pathways were observed. Stool quality remained in the acceptable range. These results suggest that the gut bacteria were able to digest the fiber bundle to produce beneficial bioactive metabolites to improve host health. This study assessed changes in canine fecal metabolites and microbiota with the consumption of foods with increasing concentrations of a fiber bundle including pecan shells, flax seed, and powders of cranberry, citrus, and beet that was previously shown (at 14% w/w) to improve stool quality, shift fecal bacterial metabolism from proteolysis to saccharolysis, increase abundance of saccharolytic bacteria, and decrease abundance of proteolytic bacteria. In this study, 48 healthy adult dogs were split evenly to consume different inclusion levels (0%, 1%, 2%, and 4%) of the fiber bundle for a 31-day period following a 28-day pre-feed period. Increases from baseline in the fecal short-chain fatty acids butyric acid, valeric acid, and hexanoic acid were observed only in the dogs that consumed the food with the 4% fiber bundle. With addition of any level of the fiber bundle, increases were seen in the polyphenols hesperidin, hesperetin, ponciretin, secoisolariciresinol diglucoside, secoisolariciresinol, and enterodiol. However, fecal microbiota and their metabolism, and stool scores were largely unaffected by the fiber bundle. Overall, addition of the fiber bundle appeared to increase bioactive metabolites of increased antioxidant and anti-inflammatory potency for beneficial to health and, at levels >= 4%, shifted gut bacterial metabolism toward saccharolysis.

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.

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.

BACKGROUND AND AIM: Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. 

METHODS: This double-blind, randomized, placebo-controlled trial on 522 H. pylori-positive adults evaluated dose-response effects of proanthocyanidin-standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13 C-urea breath testing and eradication at 45 days post-intervention. 

RESULTS: H. pylori-negative rates in placebo, low-proanthocyanidin, medium-proanthocyanidin, and high-proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high-proanthocyanidin juice twice daily (44 mg proanthocyanidin/240-mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori-negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well-tolerated. 

CONCLUSIONS: Twice-daily consumption of proanthocyanidin-standardized cranberry juice may help potentiate suppression of H. pylori infection.

Background and aim: Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. 

Methods: This double‐blind, randomized, placebo‐controlled trial on 522 H. pylori‐positive adults evaluated dose–response effects of proanthocyanidin‐standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13C‐urea breath testing and eradication at 45 days post‐intervention. 

Results: H. pylori‐negative rates in placebo, low‐proanthocyanidin, medium‐ proanthocyanidin, and high‐proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high‐proanthocyanidin juice twice daily (44 mg proanthocyanidin/240‐mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori‐negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well‐tolerated. 

Conclusions: Twice‐daily consumption of proanthocyanidin‐standardized cranberry juice may help potentiate suppression of H. pylori infection. Trial registration: ChiCTR1800017522, per WHO ICTRP.