Authors: Lucia Roncaglia Alberto Amaretti Stefano Raimondi Alan Leonardi Maddalena Rossi
Publish Date: 2011/05/26
Volume: 92, Issue: 1, Pages: 159-168
Abstract
Lignans are ubiquitous plant polyphenols which have relevant health properties being the major phytoestrogens occurring in Western diets Secoisolariciresinol SECO is the major dietary lignan mostly found in plants as secoisolariciresinol diglucoside SDG To exert biological activity SDG requires being deglycosylated to SECO and transformed to enterodiol ED and enterolactone EL by the intestinal microbes The involvement of bifidobacteria in the transformation of lignans glucosides has been investigated for the first time in this study Twentyeight strains were assayed for SDG and SECO activation They all failed to transform SECO into reduced metabolites excluding any role in ED and EL production Ten Bifidobacterium cultures partially hydrolyzed SDG giving both SECO and the monoglucoside with yields 25 When the cellfree extracts were assayed in SDG transformation seven additional strains were active in the hydrolysis Cellobiose induced βglucosidase activity and caused the enhancement of both the rate of SDG hydrolysis and the final yield of SECO only in the strains capable of SDG bioconversion The highest SDG conversion to SECO was achieved by Bifidobacterium pseudocatenulatum WC 401 which exhibited 75 yield in cellobiosebased medium after 48 h These results indicate that SDG hydrolysis is not a common feature in Bifidobacterium genus but selected probiotic strains can be combined to βglucosidebased prebiotics to enhance the release of SECO thus improving its bioavailability for absorption by colonic mucosa and/or the biotransformation to ED and EL by other intestinal microorganisms
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