Differences in fecal microbiota in different European study populations in relation to age, gender, and country: a cross-sectional study.

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.

[The CARMEN trial: increased intake of carbohydrates--simple or complex--and unchanged blood lipids in overweight subjects]. / CARMEN-studiet. Øget indtagelse af kulhydrater--simple eller komplekse--og nedsat fedtindtagelse giver moderat vaegttab og uaendrede blodlipider hos overvaegtige.

INTRODUCTION: The purpose was to investigate the long-term effect of ad libitum low-fat, high-carbohydrate diets with mainly simple or complex carbohydrates on body weight and blood lipids. MATERIAL AND METHODS: A six-months controlled randomised multicentre trial with the participation of five European centres. A total of 398 moderately obese subjects (BMI: 30.4 +/- 2.7 kg/m2, mean +/- SD) were randomised to four groups: Control diet group with normal macronutrient intake, a low-fat/high simple carbohydrate group, a low-fat/high complex carbohydrate group and a seasonal control group. RESULTS: After six months we found a drop in body weight of 1.7 kg (p < 0.05) in the simple and of 2.6 kg (p < 0.001) in the complex carbohydrate group compared with the control diet group. Fat mass decreased by 1.9 kg (p < 0.05) and 2.4 kg (p < 0.001) in the simple and complex carbohydrate group, respectively, compared with the control diet group. There were no significant changes or group differences in fasting blood lipids, glucose, insulin, or leptin. DISCUSSION: The results show that it is favourable to replace dietary fat by carbohydrates (simple or complex) in relation to body weight regulation. No detrimental effects were seen on blood lipids in contrast to previous contentions. Our results underline the importance of a low-fat/high-carbohydrate diet in the management of obesity and the ensuing health problems.