Effects of Cranberry on Gut and Metabolic Health

The consumption of plant-based foods, particularly berries, has been associated with improved health due to their high content of bioactive compounds. Among these, polyphenols-especially proanthocyanidins (PACs)-may offer protective effects against chronic diseases related to overweight and obesity. Cranberries are naturally rich in PACs and may positively influence metabolic health by modulating the gut microbiota. However, their specific effects on intestinal integrity and broader metabolic outcomes remain underexplored. The primary aim of this study is to assess the effects of cranberry supplementation on glucose metabolism, insulin sensitivity, blood lipid levels, and the composition and function of the gut microbiota in overweight and obese individuals. This randomized, double-blind, placebo-controlled, crossover clinical trial will include two 12-week intervention periods-one with a cranberry beverage and one with a placebo-separated by a 4-week washout period and preceded by a 2-week lifestyle stabilization phase. Participants will undergo comprehensive metabolic assessments (glucose control, insulin sensitivity, lipid profile), body composition analysis, gut microbiota profiling, and liver fat imaging (MRI in a subsample of female participants). Additional evaluations will include markers of inflammation, appetite regulation, intestinal health, and lifestyle factors.