Diversity of urinary excretion patterns of main ellagitannins' colonic metabolites after ingestion of tropical highland blackberry (Rubus adenotrichus) juice

Tropical highland blackberries are a rich source of ellagitannins (ETs), which are metabolized by gut microbiota to yield urolithin, a potentially bioactive compound excreted in urine up to 7 days after ingestion. Following the ingestion of 250 mL of tropical highland blackberry juice, a spot of urine from 26 volunteers collected at 51 +/- 4 h was analyzed for urolithin A and B main derivatives (aglycones and glucuronated forms). Three main groups, no or low urolithin excreters, predominantly UA derivatives excreters and predominantly UB derivatives excreters, were observed. These categories were also unambiguously observed from 9 individuals following the total excretion of ETs' main metabolites over a 4-day period after ingesting one shot of blackberry juice. Although relatively high inter- and intra-individual variabilities were observed, individuals preserved their status during different intervention periods with different amounts of El's ingested. Accurate UPLC-DAD/ESI-Q-TOF/MS2 allowed the tentative assignment of an identity to 15 other ET metabolites in urine, but profiling did not allow the discrimination of any other compounds aside from UA or UB derivatives. The results highlight the importance of the interaction of gut microbiota composition and the host endogenous excretery system, which may play a major role in the observed inter-individual variability. (C) 2013 Elsevier Ltd. All rights reserved.