In vitro reduced availability of aflatoxin B1 and acrylamide by bonding interactions with teichoic acids from lactobacillus strains

Abstract

Several studies have evidenced the ability of some lactic acid bacteria to bind dietary carcinoges, including aflatoxin B1 (AFB1) and acrylamide (AA). Cell wall teichoic acids (TAs) appear to be components of the bacterial that might participate in binding; however, the exact mechanisms are not clear. The aims of this work were to assess the ability of fourteen Lactobacillus strains to bind either AFB1 or AA, and to determine the possible molecular bonding interactions among toxins and constituents of TAs. Physical binding was assessed in aqueous solution, and the compontents of TAs were determined by evaluation of hydrolysis products of TAs. Binding was strain- and toxin-specific dependent. All AFB1-bacterium interactions were partly reversible, while AA-bacterium appeared to be irreversible. TAs from the evaluated strains consisted of poly(ribitol phosphate) polymers decorated with glucose, d-alanine and/or glycerol molecules, thus four simplified structures were proposed. Based on compositional analysis it was hypothesized that hydroxyl groups of AFB1 as well as carbonyl oxygens of both AFB1 and AA, might be involved in interactions between both toxins and the hydroxyl groups of either glucose or glycerol in TAs. The results of this work support the suggestion that specific Lactobacillus strains can reduce the bioavailability of dietary carcinogens, and provide for the first time new insights on teichoic acid structure relationships on toxin binding ability.