Journal of Functional Foods (Mar 2020)
Modulation of equol production via different dietary regimens in an artificial model of the human colon
Abstract
In order to find dietary conditions favouring endogenous equol biosynthesis, a pooled faecal homogenate from equol-producing women was used to inoculate the TIM-2 artificial model of the human proximal colon. The model was fuelled with control diets not supplemented (C) or supplemented (C-ISO) with isoflavones, and two isoflavone-containing diets rich in carbohydrate (CH-ISO) or protein (PR-ISO). Compared to the C-ISO control, the CH-ISO diet doubled the production of equol, while with the PR-ISO diet the production of equol in cultures decreased sharply. The CH-ISO diet was also associated with enhanced butyrate production. The numbers of most bacterial populations analysed did not significantly change along cultures with any of the diets. Surprisingly, counts for a gene involved in equol production (tdr) were reduced in all cultures, reflecting a reduction in the number of equol-producing bacteria. In conclusion, under the TIM-2 culture conditions established, the CH-ISO diet favoured the synthesis of equol.