Scientist - News - 11-09-2009:

Prebiotics may help to contain early-stage colon cancer
Beintema, Nienke

A recent German study shows that fermentation products of prebiotic fibres stop cell growth and promote cell death in early-stage cancer cells in the colon.

Scientists have long speculated about the ability of prebiotic fibres, such as inulin, to help prevent cancer in the gut. Clinical evidence indeed suggests that there is such a link, but so far it has remained unclear which cellular mechanisms are involved in the protective action of prebiotics.
Researchers from the Friedrich-Schiller-University in Jena, Germany, have now provided one of the pieces in this puzzle. The team published an article in the September issue of the British Journal of Nutrition that shows a direct cellular effect of the fermentation products of prebiotics. The Germans used a general prebiotic mixture of inuline and oligofructose, marketed as Synergy 1, and incubated the mixture with gut bacteria isolated from human faeces.

Cell growth and death
They then tested a control sample and the prebiotics-incubated sample for two fermentation products: short-chain fatty acids (SCFA) and deoxycholic acid (DCA). Both are known to play a role in the regulation of cell growth. Incubation with the prebiotic mixture resulted in an almost 2.5-fold increase of SCFA and a 3.4-fold decrease of DCA.
Moreover, early-stage colon cells appeared to react sensitively to these two factors, slowing their growth with higher concentrations of SCFA and lower concentrations of DCA. Later-stage cancer cells were much less sensitive. Finally, the researchers tested their samples for the presence of a protein that is an indicator of induced cell death: PARP. They found a significant increase in PARP concentrations in early-stage cancer cells that were exposed to the two fermentation products.
All in all, the team concluded that fermentation products of inulin have both growth-inhibiting and cell death-inducing effects on earlystage colon cancer cells. Although their results have yet to be translated to the in vivo situation, they suggest that their findings may have implications for the prevention of colon cancer.

More information:
Article in British Journal of Nutrition