COLONIC METABOLISM OF OLIVE OIL POLYPHENOLS: IN VITRO AND IN VIVO APPROACH

MOSSE JUANA INÉS; MARTÍN PELÁEZ SANDRA; MACIÀ ALBA; FARRÀS MARTA

Buenos Aires

Congreso; VI Conference of Poliphenols and Health; 2013

In vitro colon fermentation has been the model of choice to elucidate the metabolic fate of polyphenols in the large intestine. To acquire knowledge about colon metabolism of olive oil polyphenols we carried out an in vitro colon fermentation of hydroxytyrosol (OHT), tyrosol (Tyr), hydroxytyrosol-acetate (OHT-ac) and oleuropein (OL) using human fecal samples as microbial inoculums. The results obtained were then compared with the analysis of feces from 10 healthy adults that consumed a phenol-enriched olive oil (500 mg phenols/kg oil, 25 mL/day) during 3 weeks. Results from in vitro colon fermentation showed an important degradation of OHT and Tyr at the first 6 h of incubation; after 12 h were slightly affected by colon bacteria remaining relatively stable until 48 h of incubation. HT-ac colonic fermentation produced free HT as major metabolite. OL was mostly degraded after 12 h of incubation and give as products of it catalysis HT, HT-ac, oleuropein aglycone and the dialdehydic form of elenolic acid linked to hydroxytyrosol. Results from human feces showed an increase of the free OHT after 3 weeks of consumption of phenol-enriched olive oil, which indicate that OHT could play an important role as colon-cancer chemo-preventive.