Microbial equol production attenuates colonic methanogenesis and sulphidogenesis in vitro

Anaerobe. 2010 Mar 16.

Microbial equol production attenuates colonic methanogenesis and sulphidogenesis in vitro.
Bolca S, Verstraete W.

Laboratory of Microbial Ecology and Technology (LabMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.

Abstract
Hydrogen gas produced during colonic fermentation is excreted in breath and flatus, or removed by hydrogen-consuming bacteria such as methanogens and sulphate-reducing bacteria. However, recent research has shown that H(2) is also consumed by equol-producing bacteria during the reduction of daidzein into equol. In this study, the interactions between methanogens, sulphate-reducing, and equol-producing bacteria were investigated under in vitro simulated intestinal conditions. In the presence of daidzein, the equol-producing bacterial consortium EPC4 gave rise to equol production in cultures of Methanobrevibacter smithii or Desulfovibrio sp. as well as in faecal samples with methanogenic or sulphate-reducing abilities. Moreover, this supplementation significantly (P<0.001) decreased the methanogenesis and sulphidogenesis. The attenuation did not occur in the absence of a daidzein source. Additionally, there was no influence of soy germ powder, daidzein or equol as such, excluding a possible inhibition by these compounds. Finally, a stronger decrease was observed with increasing amounts of EPC4 and a constant equol production, suggesting that the observed effect was only partly caused by the action of daidzein as a hydrogen sink. These findings are of relevance since abdominal discomfort such as bloating and flatulence, are related to colonic gas production, whereas equol has potential health benefits. Copyright 2010 Elsevier Ltd. All rights reserved.

Per the above study, it appears that taking equol itself may not do anything, but instead the equol being converted by also be a positive factor considering the effects on hydrogen reducing bacteria, such as EPC4.

More info here:

http://jn.nutrition.org/cgi/content/full/136/4/946