A parallel, double-blind, randomised controlled trial to evaluate the effect of daily consumption of symbiotic yoghurt on lipid profile in mildly to moderately hypercholesterolemic men and women.

A parallel, double-blind, randomized controlled trial involving 96 non- smoking, overweight or obese, aged 30-65 will be recruited and randomly assigned into 3 groups to daily consume 200g of either control yoghurt containing 1.5% standard yoghurt cultures (Streptococcus thermophiles 1275 and Lactobacillus bulgaricus 1842), 2) symbiotic yoghurt containing 5% of probiotic mixture (1:1; Lactobacilus acidophilus ASCC 2404, Lactobacilus rhamnosus ASCC 1520), 2% Fructooligosaccharides (FOS) and inulin (synergy1), and 3) flavored symbiotic yogurt containing 5% of probiotic mixture (1:1; Lactobacilus acidophilus ASCC 2404, Lactobacilus rhamnosus ASCC 1520), 2% FOS and inulin (synergy1) and 20% concentrated pomegranate juice for 8 weeks. Anthropometric measurements and fasting blood samples will be collected at the beginning of the study, week 4 and 8. All participants will be instructed to maintain their usual dietary habits and lifestyle and to avoid consuming any yoghurt other than that provided to them by the researchers throughout the 8-week trial. The subjects will be also instructed to keep yoghurt under refrigeration and to avoid any changes in medication if possible. The allocation of intervention or control group will be concealed from the researchers and different yoghurt treatment containers will be identical looking. Therefore, neither the subjects nor the investigator will be aware of treatment assignments in this double blind study. Yoghurt samples will be distributed weekly by the researchers. Compliance with the yogurt consumption guidelines will be monitored via phone interviews once per week. In addition, subjects will be also asked to keep a checklist of daily yoghurt consumption throughout the study period. Information on food consumption and anthropometric measurements, and fasting blood samples will be collected at the beginning and at the end of the trial. Nutrient intakes will be estimated using a 24-h dietary recall at the beginning and at the end of the study for 3 days. Three day averages of energy and macro-nutrient intakes will be analyzed by food works software. All data entry will be performed by trained dieticians. If a participant ate a food that was not in the database, a food with very similar nutrient composition will be chosen. Nutrient information will be also obtained through food labels or recipes from participants. ANTHEROPOMETRIC MEASUREMENTS Anthropometric measurement of participants will include height, weight, waist and hip circumference, blood pressure and heart rate, and will be performed by the student researcher with the assistance of selected, trained student practitioners. Weight will be measured with digital scales and height measured with a stadiometer. Waist circumference will be measured twice with the participant standing with their arms crossed across their thorax with a tape measure placed around the body at the narrowest point between the lower costal (10th rib) border and the iliac crest. Hip circumference will also be measured twice, with the participant standing in a relaxed position with arms folded across their thorax at the level of the greatest posterior protuberance of the buttocks. Blood pressure and heart rate will be measured twice using an electronic blood pressure machine, where the inflatable cuff of the sphygmomanometer is positioned round the upper arm at the heart level. All measurements will be recorded on summary sheets contained in the participants file and stored in a secure locked filling cabinet. BLOOD COLLECTION The subjects will be directed to the nutrition clinic at the beginning of the study, week 4 and at the end of week 8 for blood tests. The blood sample will be drawn from the antecubital vein in the arm, after an overnight 8-10 h fast, at the beginning of the trial, week 4 and week 8 of intervention. The blood should be taken between 7 and 10 am on the collection day by a trained phlebotomist. The serum samples will be labelled with the participants’ code for confidentiality and stored one ice until they are centrifuged and stored at -20°c until analysed. BIOCHEMICAL ANALYSIS Blood samples will be analysed at the Health Scope Pathology Centre (St. Alban/ Werribee, Melbourne). Serum concentrations of Total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) will be measured using the standard enzymatic methods with commercially available kits.