Pilot Study on the Influence of a Synbiotic Formulation (ProSynbiotic) on Gut Microbiota Composition, Adiposity and Selected Markers of Cardiometabolic Health in Overweight or Moderately Obese Individuals

This is a parallel, double-blind, randomized, placebo controlled trial to determine the effects of a synbiotic formulation (ProSynbiotic) containing 4 billion CFU of a probiotic blend of Bifidobacterium lactis BB-12, Lactobacillus acidophilus LA-5, Lactobacillus casei 431 and Saccharomyces boulardii, along with 1 g of the prebiotic inulin and 100 mg of galactooligosaccharide (GOS) on the gut microbiota composition, body composition, expression of genes mediating dietary energy harvest and adiposity, and on adiposity-related metabolic markers in healthy free-living overweight or moderately obese subjects. The duration of the study is 18 weeks, including a 2-week run-in period before randomization of subjects into the synbiotic or placebo group, a 12-week intervention period, and a 4-week follow-up after the end of the intervention. During the intervention period, subjects will be instructed to take 3 capsules of either synbiotic or placebo per day and maintain their habitual diet and physical activity. They will also be asked to document any unusual symptoms or side effects as well as keep a bowel diary. Diet and physical activity will be monitored via 24-h dietary recalls and the global physical activity questionnaire respectively. Changes in the gut microbiota composition will be determined by measuring bacterial population levels in stool sampled collected at baseline, 6 weeks, 12 weeks and the follow up time point. Body composition will be measured using the BOD POD at baseline, 6 weeks, and 12 weeks. Gene expression levels will be assessed at baseline and 12 weeks in colonocytes (isolated from stool samples) and PBMCs (isolated from blood samples) by qPCR. Metabolic markers will be measured at baseline and 12-weeks in plasma or serum using the respective biochemical- or immuno-assays.