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; kerstin.scheu@ifg.fzk.de
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.