Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions

Decroos, Karel, Vanhemmens, Steffi, Cattoir, Sofie, Boon, Nico and Verstraete, Willy (2005) Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions. Archives of Microbiology, 183 1: 45-55. doi:10.1007/s00203-004-0747-4


Author Decroos, Karel
Vanhemmens, Steffi
Cattoir, Sofie
Boon, Nico
Verstraete, Willy
Title Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions
Journal name Archives of Microbiology   Check publisher's open access policy
ISSN 0302-8933
1432-072X
Publication date 2005-01
Year available 2004
Sub-type Article (original research)
DOI 10.1007/s00203-004-0747-4
Volume 183
Issue 1
Start page 45
End page 55
Total pages 11
Place of publication Berlin
Publisher Springer
Language eng
Subject 110801 Medical Bacteriology
Abstract Only about one third of humans possess a microbiota capable of transforming the dietary isoflavone daidzein into equol. Little is known about the dietary and physiological factors determining this ecological feature. In this study, the in vitro metabolism of daidzein by faecal samples from four human individuals was investigated. One culture produced the metabolites dihydrodaidzein and O-desmethylangolensin, another produced dihydrodaidzein and equol. From the latter, a stable and transferable mixed culture transforming daidzein into equol was obtained. Molecular fingerprinting analysis (denaturing gradient gel electrophoresis) showed the presence of four bacterial species of which only the first three strains could be brought into pure culture. These strains were identified as Lactobacillus mucosae EPI2, Enterococcus faecium EPI1 and Finegoldia magna EPI3, and did not produce equol in pure culture. The fourth species was tentatively identified as Veillonella sp strain EP. It was found that hydrogen gas in particular, but also butyrate and propionate, which are all colonic fermentation products from poorly digestible carbohydrates, stimulated equol production by the mixed culture. However, when fructo-oligosaccharides were added, equol production was inhibited. Furthermore, the equol-producing capacity of the isolated culture was maintained upon its addition to a faecal culture originating from a non-equol-producing individual.
Keyword Isoflavone
Equol
Hydrogen gas
Bacteria
FOS
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Advanced Water Management Centre Publications
 
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Created: Mon, 16 Feb 2009, 14:04:15 EST by Joanne Mellor on behalf of Advanced Water Management Centre