AUTHOR=Guadamuro Lucía , Delgado Susana , Redruello Begoña , Flórez Ana B. , Suárez Adolfo , Martínez-Camblor Pablo , Mayo Baltasar 

TITLE=Equol status and changes in fecal microbiota in menopausal women receiving long-term treatment for menopause symptoms with a soy-isoflavone concentrate

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 6 - 2015

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00777

DOI=10.3389/fmicb.2015.00777

ISSN=1664-302X

ABSTRACT=The knowledge regarding the intestinal microbial types involved in isoflavone bioavailabililty and metabolism is still limited. The present work reports the influence of a treatment with isoflavones for six months on the faecal bacterial communities of 16 menopausal women, as determined by culturing and culture-independent microbial techniques. Changes in faecal communities were analysed with respect to the womenʼs equol-producing phenotype. Compared to baseline, at 1 and 3 months the counts for all microbial populations in the faeces of equol-producing women had increased strongly. In contrast, among the non-producers, the counts for all microbial populations at 1 month were similar to those at baseline, and decreased significantly by 3 and 6 months. Following isoflavone intake, major bands in the denaturing gradient gel electrophoresis (DGGE) profiles appeared and disappeared, suggesting important changes in majority populations. In some women, increases were seen in the intensity of specific DGGE bands corresponding to microorganisms known to be involved in the metabolism of dietary phytoestrogens (Lactonifactor longoviformis, Faecalibacterium prausnitzii, Bifidobacterium spp., Ruminococcus spp.). Real-Time quantitative PCR revealed that the Clostridium leptum and Clostridium coccoides populations increased in equol producers, while those of bifidobacteria and enterobacteria decreased, and vice versa in the non-producers. Finally, the Atopobium population increased in both groups, but especially in the non-producers at three months. As the main findings of this study, (i) variations in the microbial communities over the six-month period of isoflavone supplementation were large; (ii) no changes in the faecal microbial populations that were convincingly treatment-specific were seen; and (iii) the production of equol did not appear to be associated with the presence of, or increase in the population of, any of the majority bacterial types analysed.