Effect of wheat aleurone ON the MICROBIAL GUT FLORA and on the formation of SCFA after simulated gastro-intestinal passage
1 Institute of Functional Interfaces (IFG), Department of microbiology of natural and technical surfaces, Research Centre Karlsruhe, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; firstname.lastname@example.org
2 Institute for
Nutrition, Department of Nutritional Toxicology, Friedrich-Schiller-University
3 Kampffmeyer Food Innovation GmbH, Trettaustr. 32-34, 21107 Hamburg, Germany; Michael.Gusko@Kampffmeyer.de
Prebiotics can support microbial fermentation in the gastro-intestinal tract resulting in a higher content of health-relevant metabolites, e.g. short chain fatty acids (SCFA) or antioxidants which contribute to colon cancer prevention. Prebiotics such as wheat aleurone are supposed to advance the growth of probiotics e.g. Bifidobacteria in the gut lumen. Probiotics on the other hand have the ability to enhance the effectiveness of prebiotics.
In the present study the effect of wheat aleurone on bacterial composition of the microbial gut flora and the formation of SCFA was investigated. Therefore, digestion was simulated in vitro with conditions adjusted to gastro-intestinal passage (e.g. pH, addition of bile acids and faeces) using wheat aleurone. After simulation of the gastro-intestinal passage DNA extracts of the pelletized faecal samples were subjected to qPCR for the enumeration of total Eubacteria, Lactobacilli, Bifidobacteria and Enterococci. The supernatant was used for quantification of SCFA by GC-MS.
In the presence of wheat aleurone the number of Bifidobacteria in the faeces pellet was increased from 0.37 % (control) to 6.28 % of the total bacterial counts. Cell counts for Lactobacilli and Enterococci in the faeces pellet were not influenced by the simulated digestion with wheat aleurone.
At the same time the supernatant contained 1.6 to 3.8 fold higher amounts of SCFA than the control. Moreover, the molar ratio of SCFA in the sample with wheat aleurone was shifted in favour of butyrate. This is an important factor because butyrate prevents colon cancer by initiating cell differentiation and apoptosis. These first results have to be confirmed in further investigations.