Poster Topical Area: Energy and Macronutrient Metabolism
Location: Hall D
Poster Board Number: 527
Objective: The health benefits of dietary fibers are now well recognized. These include direct effects on gut functions and digestion, but also indirect effects on blood glucose control, cardiovascular functions and host metabolism. Yet the average intake remains far below recommendations. Fiber supplementation therefore represents a realistic and efficient dietary intervention. Several products are already commercially available. Since different fibers may impact host health via different mechanisms it remains critical to evaluate their physiological effects. In this study we assessed the effects of two types of fibers: soluble corn fiber (SCF, Promitor®, Tate & Lyle) and fructooligosaccharide (FOS, Orafti P95®, Beneo) in a mouse model of diet-induced obesity.
Methods: C57BL/6J male mice (n = 15/group) were fed a control (CT) or high-fat diet (HFD) supplemented without or with SCF or FOS (10% supplemented in water) for 8 weeks. Body weight and composition (lean and fat mass) were recorded weekly. Inflammatory markers were assessed by qPCR and gut microbial composition by 16S rRNA sequencing.
Results: Both SCF and FOS similarly decreased body weight gain and fat mass without affecting caloric intake. However, energy excretion (measured by bomb calorimetry) was increased by SCF but not FOS, suggesting different mechanisms of action. For both fibers, there was a reduction of inflammation in liver (reduced MCP-1 expression) and adipose tissues (reduced levels of LBP, MCP1, CD11c), as well as an improvement of the glucose tolerance.
Interestingly, the overall improved metabolic profile was associated with a significant impact on the gut microbial composition, that showed similarities between fibers (e.g., restorations of Pseudomonas, Dehalobacterium, Sutterella and butyrate-producing Allobaculum levels; reduction of several HFD-induced bacteriaand pathogens Bacillus and Desulfovibrio), but also differences (e.g. differential changes in Blautia, Coprococcus and Parabacteroides levels, as well as that of Bifidobacterium Prevotella and Lactococcus.
Conclusion: Although dietary fibers SCF and FOS have similar physiological outcomes on mice fed a HFD, their mechanisms of action appear to be different.
Matthias Van Hul
Université catholique de Louvain
Woluwe-Saint-Lambert, Brussels Hoofdstedelijk Gewest, Belgium