title: Study of the catabolism of thyme phenols combining in vitro fermentation and human intervention.
abstract: The gut metabolism of four thyme phenolics (monoterpenes thymol and carvacrol, rosmarinic acid, and eriodictyol) was evaluated in vitro. After the in vitro transformations of the individual phenols had been studied, the presence of their microbial metabolites was investigated in human feces collected before and after a sustained intake (3 weeks) of 25 mL/day of a thyme phenol-enriched olive oil. Results of in vitro fermentation showed low degradation of thymol and carvacrol. By contrast, large catabolism was noted when rosmarinic acid and eriodictyol were fermented, yielding hydroxyphenylpropionic acid as the main metabolite. In accordance with these results, after the in vivo intervention with thyme phenol-enriched olive oil, an increase in the concentration of hydroxyphenylpropionic and phenylpropionic acids was observed in human feces, confirming the effective in vivo microbial degradation of rosmarinic acid and eriodictyol. Carvacrol was detected in fecal samples at trace levels, suggesting that monoterpenes are well absorbed in the upper part of the gastrointestinal tract.
authors.affiliation: Food Technology Department, UTPV-XaRTA, Agrotecnio Research Center - University of Lleida , Av/Alcalde Rovira Roure 191, 25198 Lleida, Spain.
authors.forename: Juana I
authors.initials: JI
authors.lastname: Mosele
authors.forename: Sandra
authors.initials: S
authors.lastname: Martín-Peláez
authors.forename: Alba
authors.initials: A
authors.lastname: Macià
authors.forename: Marta
authors.initials: M
authors.lastname: Farràs
authors.forename: Rosa-Maria
authors.initials: RM
authors.lastname: Valls
authors.forename: Úrsula
authors.initials: Ú
authors.lastname: Catalán
authors.forename: María-José
authors.initials: MJ
authors.lastname: Motilva
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D005285:Fermentation; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D064307:Microbiota; D008954:Models, Biological; D000069463:Olive Oil; D010636:Phenols / Q000737:chemistry / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism*; D010938:Plant Oils / Q000378:metabolism; D046930:Thymus Plant / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000069463:Olive Oil; D010636:Phenols; D010936:Plant Extracts; D010938:Plant Oils
keywords: colonic metabolites; in-vitro colonic fermentation; thyme monoterpenes; thyme phenols