Evaluation of anti-inflammatory properties of different sources of wheat grain dietary fibres – WHEAFI

This project aims at determining the capacity of the cereal products enriched in dieatry fibers to reduce the chronic inflammatory processes in overweight people.
Food (bread, pastas, biscuits) enriched with sources of fermentable and non-fermentable dietary fibers, is used to estimate during a clinical study the effects of high-fiber diets on the markers of inflammation. This approach is completed by an evaluation of the acceptability of food enriched in dietary fibers. Furthermore new methods for the assay of dietary fibers allowing in particular to estimate their fermentable feature, are developed within the project.

The first step of this project was to produce dietary fibers presenting contrasted features and to incorporate them into food to obtain a contribution in dietary fibers of the order of 15g / day compared to a reference diet. A process of abrasion was selected to produce fractions (F +) rich in aleurone layer and containing fermentable dietary fibers and fractions rich (F-) in outer pericarp containing lowly fermentable dietary fibers. The incorporation of the fractions F + and F-, in bread, pastas and biscuits, was optimized by the industrial partners of the project. According to food a supplement of dietary fibers from 5 % to 8 % compared with the reference food is brought by the incorporation of the fractions F + and F-. This optimization of food and a daily consumption of 150g of bread, 80g of pastas and of 25g of biscuits allows to reach the objective of a supplement of 15g of fibers a day in the diet.
At the same time the main methods of dosage of dietary fibers were compared to have an accurate assay of the content in dietary fibers of the food of the project. The use of more specific methods allowing in particular to distinguish the fermentable and non-fermentable dietary fibers is evaluated.
The effect of the fermentable and non-fermentable high-fiber diets will be estimated on 50 healthy overweight volunteers. Each of the diets (F +, F, reference) will be followed during a period of 4 weeks, separated by a wash out period from 4 to 6 weeks.The recruitment of the volunteers will begin in September, 2012 and the clinical follow-up of the physiological parameters and the markers of the inflammation will spread out from October, 2012 till May, 2013.

The consumption of wheat bran has an effect on the regulation transit time well known in general public and validated by numerous studies of the scientific community.
Numerous studies suggest that the effect of dietary fibers is not limited to «transit time« and that their consumption ihas other beneficial effects in particular on the inflammation status. By establishing a specific effect of fermentable dieatry fibers of wheat on the inflammation, this project will on one hand allow to develop new products enriched in fibers and on the other hand will lead to revisit the milling processes in order to get fraction of higher nutritional interest. Besides the demonstration of a specific effect of fermentable dietary fibers will support the development of cultivars with high-fiber content in the starchy endosperm of grain.

First résults of WHEAFI project were presented during the 5th International Dietary Fibre Conference - DF-2012 - 7-9 mai 2012 Rome – Italiy. (http://df2012.icc.or.at/ ).
1) Wheat fibre selection using dry fractionation process. Barron C, Chaurand M, Samson M-F, Abecassis J (Communication orale)
2) Elisa assay of arabinoxylans and AXOS. Tranquet O., V. Echasseriau V, Looten R and Saulnier L (Poster)

Cardiovascular diseases, diabetes and obesity are major health problems in Western Europe and Northern America. The general nutritional recommendation is a lowering of lipids intake and an increase in the consumption of complex carbohydrates, with a promotion of food exhibiting a low Glycemic Index and a high dietary fibre content. Today the dietary fibre intake fails to meet the recommendations and in most cases the trend for population is to eat less fibre not more. The cereals products, one of the pillars of a healthy diet, clearly might help to increase dietary fibre intake in French population.

The WHEAFI project aims at developing cereal food enriched with fibre selected for their nutritional properties. The objective of this project is to determine the ability of fibre enrichment to reduce chronic inflammatory processes in overweight population. These results could be extrapolated to the reduction of chronic nutrition diseases (as diabetes and CVD) in general population. Systemic inflammation is increasingly recognized as an important mediator of coronary artery disease, chronic degenerative diseases such as diabetes and Alzheimer dementia and other chronic diseases such as metabolic syndrome and obesity. Epidemiological studies have shown the reduction of coronary heart disease, of oxidant stress and of inflammation by intake of dietary fibre, cereal fibre (wheat bran) and whole grain. Unexpectedly, there are some contradictory results between studies that have evaluated the short and long term effects of wheat bran and whole grains on human health. However depending on their specific chemical structure, physico-chemical property (solubility/viscosity) and fermentation ability, cereal dietary fibre may have considerable different extent of effects. The main hypothesis of this project is that prebiotic effect of specific wheat dietary fibres (endosperm, aleurone), modulation of colic microflora and formation of SCFA (butyrate) contribute to the reduction of inflammatory process. A clinical study with food enriched in different wheat dietary fibres is proposed to explore the potential favourable effects as observed epidemiologically, and to understand the anti-inflammatory effect and long-term reduction of chronic diseases. In addition, new assay methods will be developed to assay AX and grain tissues. These assays will help to select wheat dietary fibres for their nutritional effects.

This project gathers academic and industrial partners in order to bring new insights in the domain of nutrition and to help the development of cereal products with an improved nutritional quality.