Cranberry reduces low fiber, animal-based diet effects on gut health

In a recently published feeding trial in The Journal of Nutritional Biochemistry, scientists investigated the potential protective effect of cranberries on the gut microbiome with an animal-based diet. Consuming cranberry compounds modified the impact of an animal-based diet in study participants by restoring a healthier microbiota profile. The addition of whole cranberry powder lessened potentially carcinogenic secondary bile acids and blunted the decline in beneficial short chain fatty acids (SCFA) in the gastrointestinal (GI) tract.

"Among the 20 most commonly consumed fruits in the American diet, we chose to investigate cranberries and the gut microbiome as they are among the fruits with a high total phenol content," said study author, Dr. Oliver Chen. Dr. Chen further explained the importance of the investigation because the gut microbiota is a key protector for human health. "An imbalance can increase the risk for several chronic diseases, including atherosclerosis, hypertension, kidney disease and type 2 diabetes," added Dr. Chen. "Identifying foods - like cranberries - that can help shape and support a healthier gut microbiome could have a remarkable impact on public health."

An international team led by researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, conducted a randomized, double-blind, crossover study of 11 healthy subjects (7 males, 4 females) aged 25 to 54 years with normal digestive function. A control diet, comprised of meats, dairy products and simple sugars was compared to a treatment diet - the control diet plus 30 grams of freeze-dried whole cranberry powder - for two, 5-day periods with a 2-week washout in between. The cranberry diet showed fewer potentially negative microbiota changes than the control diet phase. It appeared that adding cranberries to the control diet reduced the rise in secondary gut bile acids that have been associated with colon and GI cancer. Cranberries also lessened the drop in beneficial SCFA thought to help maintain healthy GI cells. Overall, the treatment diet suggested that cranberry constituents may help support a healthy gut microbiome.