Dietary fibres: their kinetics of fermentation inside the human gut lumen, and its effects on human metabolism in vivo

Consumption of non-digestible carbohydrates (NDC) has been linked to many health benefits. However, detailed knowledge on the exact fate and impact of NDC in the human intestinal tract is lacking.

In this project we propose to perform a fully controlled dietary intervention study in humans using one NDC. A new electronic medical delivery/sampling device, the IntelliCap system, will be applied. This allows the simultaneous and direct investigation of changes in host metabolism, dynamics of the gut microbiota and NDC-degradation/fermentation. Delivery of 13C-labeled SCFA permits the investigation of fermentation kinetics and substrate utilization in the host.

We will apply this approach in a randomized-controlled, cross-over feeding trial with a diet that will be low or high in one NDC and will include 10 overweight middle-aged men. Luminal content of the distal small intestine will be sampled concomitantly with repeated blood sampling after an oral bolus of NDC and subsequent luminal delivery of 13C-labeled SCFA. Samples will be analysed for a variety of components, including microbiome composition, carbohydrate degradation products, and metabolites and hormones in plasma.

Building on our previous, analogous work in mice, systems biology approaches will be used to integrate the obtained data. In this way we will be the first to assess the luminal activity of the gut microbiota upon delivery of fermentable NDC along with its effects on human physiology.

More research: Nutritional systems biology of the intestine as gatekeeper