In the News, Winter 2021 - 22: Polyphenol-Rich Foods Can Help Seal a Leaky Gut

The journal Clinical Nutrition recently published a new analysis of the MaPLE trial (Microbiome mAnipulation through Polyphenols for managing Leakiness in the Elderly), which ran from 2016 to 2019. This randomized controlled trial investigated the effects of an eight-week, polyphenol-rich diet on the gut microbiota and permeability of the intestinal wall. Stool samples were analyzed to assess changes to the microbial population while the protein zonulin was employed as the marker for gut leakiness.

Fifty-one elderly individuals participated in the study, and the diet consisted of three daily portions of polyphenol-rich foods, including blood oranges, pomegranate juice, green tea, apples, dark chocolate, and berries. A previous report on the trial found that, compared to the control diet, the diet rich in polyphenols significantly increased the numbers of SCFA (short-chain fatty acid)-producing bacteria and decreased excessive permeability of the gut wall. The most recent analysis observed a correlation between food-derived metabolites in the blood and an improvement in the inflammatory environment of the gut as a result of the dietary intervention.

SCFAs nourish the epithelium of the small and large intestines and play a large role in regulating the immune system. In addition, increased permeability of the gut barrier is concretely regarded as a major contributor to the development of autoimmunity. This is primarily due to a leaky gut allowing for systemic inflammation to be ignited by way of bacterial toxins and other invaders gaining access to the bloodstream.

Intestinal permeability is modulated in large part by the bacteria constituting the gut microbiome. As the authors of the paper concluded, upping the intake of fruits, vegetables, and other plant foods may help to counteract a leaky gut and attenuate the severity of a present autoimmune condition.

Source: Peron G, Gargari G, Merono T, et al. Crosstalk among intestinal barrier, gut microbiota and serum metabolome after a polyphenol-rich diet in older subjects with “leaky gut”: The MaPLE trial. Clinical Nutrition, 2021; 40(10): 5288-5297. DOI: 10.1016/j.clnu.2021.08.027.