Effect of Cranberry Juice Supplementation on the Gut Microbiome and Inflammatory Markers: A Randomized, Double-Blind, Placebo-Controlled Study in Overweight Individuals.

OBJECTIVES: Obesity is considered a growing public health concern worldwide. This complex chronic disease has been linked with alterations in adipose tissue and increased pro-inflammatory molecules. Previous studies have associated cranberry (Vaccinium macrocarpon) polyphenols with antimicrobial effects anti-inflammatory activities. In this study, we evaluate the impact of daily cranberry juice consumption for six weeks on the gut microbiome and inflammatory cytokines of overweight individuals. METHODS: A total of 45 overweight or obese (BMI 28–35 kg/m(2)) individuals aged 18–65 years, with a body fat percentage greater than 18% for males and 25% for females consumed 8 oz of placebo or cranberry juice twice a day for six weeks. Blood, fecal samples, intestinal health questionnaires, and food records were collected at baseline and after six weeks. Inflammatory cytokines, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), IL-6, IL-8, IL-10, interferon γ (IFN-γ), were analyzed in serum. DNA was extracted from fecal samples to perform a 16S rRNA metagenomics analysis. RESULTS: Serum levels of TNFα were significantly decreased in the male group (p-value < 0.0317), and IL-8 levels were significantly increased in the female group (p-value < 0.0121) after six weeks of cranberry consumption. In contrast, cranberry consumption significantly improved constipation status after six weeks, based on the AGACHAN questionnaire. At the end of the study, significant differences were found among groups on the class Coriobacteriia, attributed to an increment in the relative abundance of unidentified Coriobacteriaceae sp. after cranberry consumption. Moreover, significant differences among groups on the Bilophila genus were detected after six weeks. This difference was accompanied by an increase in the relative abundance of unidentified Bilophila sp. on the placebo group. CONCLUSIONS: A short-term supplementation of a low dose of cranberry juice showed a slight impact on the inflammatory markers and increased the abundance of some beneficial bacterial species. Results are contributing to understanding the bioactive properties of cranberry polyphenols. FUNDING SOURCES: Ocean Spray Cranberries, Inc.