A cross-sectional study on intestinal microbiota composition was performed on 230 healthy subjects at four European locations in France, Germany, Italy, and Sweden. The study participants were assigned to two age groups: 20 to 50 years (mean age, 35 years; n ‫؍‬ 85) and >60 years (mean age, 75 years; n ‫؍‬ 145). A set of 14 group-and species-specific 16S rRNA-targeted oligonucleotide probes was applied to the analysis of fecal samples by fluorescence in situ hybridization coupled with flow cytometry. Marked country-age interactions were observed for the German and Italian study groups. These interactions were inverse for the predominant bacterial groups Eubacterium rectale-Clostridium coccoides and Bacteroides-Prevotella. Differences between European populations were observed for the Bifidobacterium group only. Proportions of bifidobacteria were two-to threefold higher in the Italian study population than in any other study group, and this effect was independent of age. Higher proportions of enterobacteria were found in all elderly volunteers independent of the location. Gender effects were observed for the Bacteroides-Prevotella group, with higher levels in males than in females. In summary, age-related differences in the microbiota makeup were detected but differed between the study populations from the four countries, each showing a characteristic colonization pattern.

Olive oil is more than a monounsaturated fat. Its phenolic content can also provide benefits for plasma lipid levels and oxidative damage. International Standard Randomised Controlled Trial number: ISRCTN09220811.

Objective-Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. Approach and Results-A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed.Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and −2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL 2 ) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL 3 ) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. Conclusions-Olive