FiberTAG

Background and aim

The FiberTAG project has established a set of biomarkers linking dietary fiber (DF) intake and gut microbiota-related health effect. We aim at refining the concept of DF based on novel biological effects that can occur upon gut microbiota-nutrients interaction by using existing cohorts and by developing innovative approaches to evaluate the health interest of novel insoluble DF.

The FiberTAG consortium gathers 4 academic principal investigators from Belgium, France, Germany and Canada, respectively. They gather complementary research expertises such as 1) host physiology with emphasis on management of cardio-metabolic disorders, 2) intervention studies based on diet and prebiotic DF, 3) microbial ecology, 4) data integration and modelling. Two industrial partners (Kitozyme and Mondelez) have developed and provided selected insoluble fiber for the intervention studies.

Specific metabolites selected as biomarkers of microbiota-driven fermentation and gut-related functions have been analyzed in 5 existing cohorts of healthy or overweight  populations in which the fecal microbiota composition and DF intake have been analyzed. New intervention studies has been performed in healthy and cardiometabolic risk volunteers to evaluate the interest for health of two insoluble fibers (chitin-glucan and a wheat bran fraction).

Expected impact

Establishment of a set of biomarkers linking DF intake and gut-microbiota related health effect. We aim at refining the concept of DF based on biomarkers of key biological effects related to gut microbiota in the context of cardio-metabolic risks.

A repertoire of DF detailing soluble versus insoluble, and (oligo)saccharides fermentable (inulin, galactooligosaccharides, fructooligosaccharides) and their occurrence in food products consumed in Europe has been established. This new repertoire is a tool to evaluate in the food questionnaires, food diary, 24h-recall used for the cohorts the potential to calculate the total amount as well as type of DF which have been ingested by the volunteers in the corresponding cohorts. It will be made available to the scientific committee of the field and used in the future clinical studies through its publication in a scientific journal.

A specific food frequency questionnaire (FFQ) assessing the consumption of dietary fibers (quality, including insoluble fibers and quantity) has been developed. Given the significant well-known metabolic effects of the dietary fiber on health and especially on the gut microbiota, this questionnaire will be a unique tool which will remedy to the lack of existing dietary questionnaires in this field. This questionnaire will be available to the scientific committee of the field and used in the future clinical studies.

Targeting VOC has solid scientific foundation, and may provide new ways of investigating the effects of the gut microbiota derived metabolites. Access to these metabolites, their quantity, quality, kinetics could help to understand the precise metabolic impacts of the nutrients (including the dietary fibers) on the gut microbiota but also on different targeted organs. In the FiberTAG project, we have developed a new non-invasive analytic method to identify and measure the VOC from exhaled gaz. This method will be published and thus made available to the scientific community of the field.

The research project contribute to fill the knowledge gap by comparing the immunological and metabolic effects of fibre, and determine the influence of fibre on gut microbiome, inflammatory, metabolic and hormonal markers (namely through data obtained from the FYBER and FOOD4GUT cohorts).

The research project provides evidence for potential mechanistic links between human health outcomes of fiber supplementation and the gut microbiota, which may allow for improved clinical efficacy once the mechanistic bases for these links are established.

The research project investigates possible changes in the gut barrier function as well as the microbiota in association with dietary fiber intake. With the results of the FiberTAG project new recommendations for the dietary fiber intake, considering the development and stabilization of a healthy gut barrier and microbiota, can be established.

So far the metabolism and the health-related impact of short chain fatty acids (SCFAs), bile acids (BA) and conjugated PUFA (cPUFA) are not satisfactorily understood. The FiberTAG project analyses intestinal SCFA, BA and cPUFA production in several aspects, including effects on the gut barrier, the gut microbiota and eventually health effects in about 1000 subjects. The FiberTAG project may therefore contribute to better understand SCFA, BA and cPUFA and their impact on health. Furthermore, the project established specific food questionnaires to determine the intake of different kinds of dietary fibers and will investigate which SCFAs are produced from which dietary fibers. The FiberTAG project can therefore develop recommendations for dietary fiber intake in the context of SCFA/BA/cPUFA production and its impact on health.

The effects of dietary fibers supposedly vary in-between different health conditions. By including several different at-risk cohorts (alcoholism, obesity, high-risk of cancer) new individualized recommendations for different medical conditions can be developed.

The impact of the chitin-glucan fiber on the intestinal microbiota  was more deeply substantiated using newly developed and validated biomarkers. This project will maybe allow to generate new health claims related to the investigated fibers. The measurement of exhaled gas and metabolites, as a biomarker is simple and appropriate method/approach, easily follow by medical practitioner. To our best knowledge, this approach will provide a unique selling proposition on the market and maybe open new perspectives for insoluble fermentable fibers in the field of intestinal health.