P0252 - Increased Urolithin a Production in Patients Given a Fixed Amount of Ellagic Acid in the Form of Walnuts Is Correlated With Baseline Urolithin A Levels

John W. Birk, MD, FACG¹, Joseph C. Anderson, MD², Amy Pallotti, BA³, Daniel Rosenberg, PhD^4
1University of Connecticut Health Center, Farmington, CT; ²University of Connecticut School of Medicine, Hanover, NH; ³UCONN Health, Farmington, CT; ⁴UCONN Health, Farmington, DE

Introduction: Urolithin A (UroA) is a potent antioxidants and anti-inflammatory agent. UroA and other urolithins are believe to be beneficial for general health and might be chemo preventive for colorectal cancer(CRC). Urolithins are produced by the colonic microbiome using ellagic acid (EA) as a substrate. It is not well established what microbiome or other factors effect UroA production. In order to evaluate other factors in UroA production we gave a continuous amount of a food supplement (walnuts) rich in EA and measured the increase in urinary UroA levels. We then evaluated other factors that might effect UroA production.

Methods: 40 patients were evaluated for urinary UroA production. On intake patients filled out a 3 month food frequency questionnaire to determine their daily EA consumption and then told to avoid EA rich foods for one week as a washout period. A baseline urinary UroA level was then obtained and then patients ate 2oz a day of Walnuts for 3 weeks. At the end of three weeks another urinary sample for UroA levels was obtained. Age, Sex, BMI, Current smoking and prior daily EA consumption, was compared to amount of increase UroA production. The outcome was change in UroA levels as dichotomized by the median. Fisher’s exact or Chi square was used to compare proportions and Mann Whitney (non parametric) test was used to compare continuous variables.

Results: On a binary comparison of those above the mean increase in UroA production with those below the mean increase in UroA no significant differences were seen in Age, Sex, BMI, Current Smoking or prior EA consumption. However, baseline UroA levels were significantly correlated with increased UroA production. Patients in the lower increase of UroA group after eating walnuts had a mean baseline of 27.5 ug/ml and those in the higher increase group after eating Walnuts had a baseline of 82.5 which was significant at the p< 0.05 level.

Discussion: Urolithins might be worthwhile chemo preventive agent for CRC and further investigation is warranted on it’s colonic effects. Additionally our study suggests that ingestion of a supplement rich in the substrate molecule (EA) isn’t the only factor in robust UroA production. Robust EA consumption increases more dramatically UroA in those that are already producing higher UroA levels. Other factors such as possibly a specific microbiome are needed.



Disclosures:


John W. Birk, MD, FACG¹, Joseph C. Anderson, MD², Amy Pallotti, BA³, Daniel Rosenberg, PhD⁴. P0252 - Increased Urolithin a Production in Patients Given a Fixed Amount of Ellagic Acid in the Form of Walnuts Is Correlated With Baseline Urolithin A Levels, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.