1. Definition and Source Urolithin A is a bioavailable metabolite produced by the gut microbiota. Its precursors are ellagitannins and ellagic acid, which are found in various fruits and nuts such as pomegranates, strawberries, and walnuts. It is crucial to note that the human body cannot produce Urolithin A on its own. Its generation is entirely dependent on the metabolism of dietary ellagitannins by specific gut bacteria (e.g., Lactobacillus gasseri). Therefore, an individual's ability to produce Urolithin A, and the amount produced, depends on the presence of these specific gut microbes and the intake of ellagitannin-rich foods.
