The Effect of Prebiotic Fibres on Weight Loss in an Overweight and Obese Population

Overview

The aim of this study is to investigate whether a diet supplemented with two prebiotic fibres induces greater changes in body weight compared to placebo during 12 weeks of energy restriction in an obese/overweight population. The hypothesis is that the fiber-containing dietary supplement will: 1\) Induce greater changes in body weight compared to the placebo group 2) change the gut microbiota composition 3) improve glucose homeostasis 4) decrease serum concentration of triglycerides, total and LDL cholesterol The hypothesis is that the effect of the intervention on weight loss will be partly mediated by the diet-induced changes in the gut microbiota composition.

Prebiotics are nutrients that specifically utilized by the gut microbiota. Beneficial health effects of prebiotics are generally attributed to 1) stimulation of beneficial bacteria and SCFA production, and consequently; improved barrier function, regulation of enteroendocrine peptide secretion and resistance to inflammatory stimuli; 2) modulation of lipid metabolism, possibly by suppression of lipogenic enzymes and thus decreased synthesis of lipoproteins and triglycerides; and 3) increased mineral absorption. Inulin is recognized as a common prebiotic. Fibersol-2 is a resistant starch that has been suggested to induce satiety, when given in a dose of 10 g. Intake of inulin has been shown to induce changes in the microbial abundance and increase production of SCFA19; whereas resistant starch has been shown to improve insulin sensitivity and postprandial glucose AUC20. However, the effects of an intervention with a combination of these two fibers on obesity and body composition during an energy restricted diet have not been addressed. Supplements with other types of fibres in addition to energy restriction have shown additional effects in weight reduction. In this study, the effects of a combination product of two prebiotic fibres on additional weight loss during energy restriction in a placebo-controlled, randomized parallel study with a duration of 12 weeks will be tested. Furthermore, the effects of the fibres on the gut microbial composition, markers of metabolic syndrome (MetS) and glucose metabolism will be tested. The active diet will contain intervention products high in dietary fibre and the placebo diet will contain maltodextrin. The fiber-containing dietary supplements will add approximately 20 g of prebiotic fibres per day, where approximately 10 g will be inulin and approximately 10 g will be resistant maltodextrin. The intervention products and placebo will be consumed as milk. The fiber-containing dietary supplement is expected to induce additional weight loss, compared to placebo and to affect the gut microbiome and markers of metabolic disease.