Influence of probiotic microorganisms on aflatoxins B1 and B2 bioaccessibility evaluated with a simulated gastrointestinal digestion

Aflatoxins (AFs) are produced mainly by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxin
B1 (AFB1) is classified as carcinogenic to humans. The aim of this study was to evaluate the capacity of
different strains of Lactobacilli (Lb.) and Bifidobacteria (Bf.) to reduce the bioaccessibility of AFB1 and
aflatoxin B2 (AFB2), spiked in loaf bread, using a dynamic in vitro simulated gastrointestinal digestion
system. Aliquots of 20 mL of gastric and duodenal fluids were sampled for the determination of the
mycotoxins gastric and duodenal bioaccessibility respectively, by liquid-chromatography coupled to the
mass spectrometry in tandem (LC–MS/MS). A reduction of AFs bioaccessibility compared to the control
(digestion without bacterial strains) was evidenced. The strains that evidenced the highest gastric and
duodenal bioaccessibility reductions of AFB1 and AFB2 were Lb. johnsoni CECT 289, Lb. reuteri CECT 725,
Lb. plantarum CECT 220 and Lb. casei CECT 4180, with values ranging from 76.38 to 98.34% for AFB1 and
from 77.14 to 98.66% for AFB2. These results suggest that a food enriched with specific probiotic
microorganisms and consumed at the same time as food contaminated with AFs, could reduce the risk
associated to the intake of these toxic compounds contained in food.