Direct supplementation with Urolithin A overcomes limitations of dietary exposure and gut microbiome variability in healthy adults to achieve consistent levels across the population.
Level 2 - randomized trial
Individual randomized controlled trial measuring plasma bioavailability and microbiome profiles.
PubMed 34117375 · doi:10.1038/s41430-021-00950-1
What was done
In a randomized trial of 100 healthy adults, participants were evaluated for urolithin A (UA) producer status using dietary pomegranate juice (PJ) and randomized 1:1 to receive either PJ or a food product containing 500 mg of UA. Fecal samples, diet questionnaires, and serial plasma samples were analyzed to assess gut microbiome composition and circulating levels of UA and its conjugates.
What was found
At baseline, 12% of subjects had detectable UA. Following PJ intake, approximately 40% of subjects converted precursor compounds into UA. UA producers had significantly higher gut microbiome diversity and a higher ratio of Firmicutes to Bacteroides than non-producers. Direct supplementation with 500 mg UA provided a >6-fold higher plasma exposure compared to PJ (p < 0.0001).
Why it matters
Most healthy adults lack the microbiome capacity to convert dietary ellagitannins into urolithin A, demonstrating that direct supplementation provides consistent plasma levels across a population.
Limits
The abstract does not report downstream clinical, functional, or mitochondrial health outcomes, focusing solely on pharmacokinetic exposure and microbiome markers. Exact numerical plasma concentrations, dispersion measures, and demographics beyond healthy adults are not detailed.
Cited by
- supports Urolithin A is produced by gut bacteria from ellagitannins found in foods such as pomegranates.
- supports Approximately 50% of the human population lacks the gut bacteria required to synthesize urolithin A from diet.