title: Effect of virgin olive oil and thyme phenolic compounds on blood lipid profile: implications of human gut microbiota.
abstract: OBJECTIVE
  To investigate the effect of virgin olive oil phenolic compounds (PC) alone or in combination with thyme PC on blood lipid profile from hypercholesterolemic humans, and whether the changes generated are related with changes in gut microbiota populations and activities.
  
  
  METHODS
  A randomized, controlled, double-blind, crossover human trial (n = 12) was carried out. Participants ingested 25 mL/day for 3 weeks, preceded by 2-week washout periods, three raw virgin olive oils differing in the concentration and origin of PC: (1) a virgin olive oil (OO) naturally containing 80 mg PC/kg, (VOO), (2) a PC-enriched virgin olive oil containing 500 mg PC/kg, from OO (FVOO), and (3) a PC-enriched virgin olive oil containing a mixture of 500 mg PC/kg from OO and thyme, 1:1 (FVOOT). Blood lipid values and faecal quantitative changes in microbial populations, short chain fatty acids, cholesterol microbial metabolites, bile acids, and phenolic metabolites were analysed.
  
  
  RESULTS
  FVOOT decreased seric ox-LDL concentrations compared with pre-FVOOT, and increased numbers of bifidobacteria and the levels of the phenolic metabolite protocatechuic acid compared to VOO (P < 0.05). FVOO did not lead to changes in blood lipid profile nor quantitative changes in the microbial populations analysed, but increased the coprostanone compared to FVOOT (P < 0.05), and the levels of the faecal hydroxytyrosol and dihydroxyphenylacetic acids, compared with pre-intervention values and to VOO, respectively (P < 0.05).
  
  
  CONCLUSIONS
  The ingestion of a PC-enriched virgin olive oil, containing a mixture of olive oil and thyme PC for 3 weeks, decreases blood ox-LDL in hypercholesterolemic humans. This cardio-protective effect could be mediated by the increases in populations of bifidobacteria together with increases in PC microbial metabolites with antioxidant activities.
authors.affiliation: Cardiovascular Risk and Nutrition Research Group, REGICOR Study Group, Hospital del Mar Research Institute (IMIM), Doctor Aiguader 88, 08003, Barcelona, Spain. s.martin.pelaez@gmail.com.|Spanish Biomedical Research Networking Centre (CIBER), Physiopathology of Obesity and Nutrition (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain. s.martin.pelaez@gmail.com.
authors.forename: Sandra
authors.initials: S
authors.lastname: Martín-Peláez
authors.affiliation: Food Technology Department, UTPV-XaRTA, Agrotecnio Research-Center, University of Lleida, Av. Alcalde Rovira Roure 191, 25198, Lleida, Spain.
authors.forename: Juana Ines
authors.initials: JI
authors.lastname: Mosele
authors.affiliation: Human Pharmacology and Clinical Neurosciences Research Group, IMIM, Doctor Aiguader 88, 08003, Barcelona, Spain.|Universidad Autónoma de Barcelona, Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Pizarro
authors.affiliation: Cardiovascular Risk and Nutrition Research Group, REGICOR Study Group, Hospital del Mar Research Institute (IMIM), Doctor Aiguader 88, 08003, Barcelona, Spain.|Spanish Biomedical Research Networking Centre (CIBER), Physiopathology of Obesity and Nutrition (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.|Universidad Autónoma de Barcelona, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Farràs
authors.affiliation: Spanish Biomedical Research Networking Centre (CIBER), Physiopathology of Obesity and Nutrition (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.|Human Pharmacology and Clinical Neurosciences Research Group, IMIM, Doctor Aiguader 88, 08003, Barcelona, Spain.|Universitat Pompeu Fabra, (CEXS-UPF), Barcelona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: de la Torre
authors.affiliation: Cardiovascular and Genetic Epidemiology Research Group, REGICOR Study Group, IMIM, Doctor Aiguader 88, 08003, Barcelona, Spain.|Spanish Biomedical Research Networking Centre (CIBER), Epidemiology and Public Health (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Isaac
authors.initials: I
authors.lastname: Subirana
authors.affiliation: Department of Physiology, Faculty of Pharmacy, Institute for Research on Nutrition and Food Safety (INSA-UB), B building, Joan XXIII, 27-30, 08028, Barcelona, Spain.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Pérez-Cano
authors.affiliation: Cardiovascular Risk and Nutrition Research Group, REGICOR Study Group, Hospital del Mar Research Institute (IMIM), Doctor Aiguader 88, 08003, Barcelona, Spain.|Spanish Biomedical Research Networking Centre (CIBER), Physiopathology of Obesity and Nutrition (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Castañer
authors.affiliation: Unit of Farmacobiology, Facultat de Medicina i Ciències de la Salut, Universitat Rovira I Virgili, Sant Llorenç 21, 43201, Reus, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Solà
authors.affiliation: Unit of Farmacobiology, Facultat de Medicina i Ciències de la Salut, Universitat Rovira I Virgili, Sant Llorenç 21, 43201, Reus, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Fernandez-Castillejo
authors.affiliation: Cardiovascular Risk and Nutrition Research Group, REGICOR Study Group, Hospital del Mar Research Institute (IMIM), Doctor Aiguader 88, 08003, Barcelona, Spain.
authors.forename: Saray
authors.initials: S
authors.lastname: Heredia
authors.affiliation: Human Pharmacology and Clinical Neurosciences Research Group, IMIM, Doctor Aiguader 88, 08003, Barcelona, Spain.|Universitat Pompeu Fabra, (CEXS-UPF), Barcelona, Spain.
authors.forename: Magí
authors.initials: M
authors.lastname: Farré
authors.affiliation: Food Technology Department, UTPV-XaRTA, Agrotecnio Research-Center, University of Lleida, Av. Alcalde Rovira Roure 191, 25198, Lleida, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Motilva
authors.affiliation: Cardiovascular Risk and Nutrition Research Group, REGICOR Study Group, Hospital del Mar Research Institute (IMIM), Doctor Aiguader 88, 08003, Barcelona, Spain. mfito@imim.es.|Spanish Biomedical Research Networking Centre (CIBER), Physiopathology of Obesity and Nutrition (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain. mfito@imim.es.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Fitó
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004032:Diet; D004311:Double-Blind Method; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D000069463:Olive Oil / Q000008:administration & dosage* / Q000737:chemistry; D010349:Patient Compliance; D010636:Phenols / Q000008:administration & dosage*; D046930:Thymus Plant / Q000737:chemistry*; D014280:Triglycerides / Q000097:blood
chemical_list: D000975:Antioxidants; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D000069463:Olive Oil; D010636:Phenols; D014280:Triglycerides
keywords: Bifidobacteria; Cholesterol; Gut microbiota; Phenolic compounds; Prebiotic; Virgin olive oil; ox-LDL