Binding of aflatoxin B-1 to bifidobacteria in vitro

Aflatoxins are mycotoxins that cause health and economic problems when they contaminate food and feed. One potential method for reducing human health effects due to aflatoxin ingestion is to block uptake via binding by bacter ia that either make up the normal gut flora or are present in fermented foo ds in our diet. These bacteria would bind aflatoxin and make it unavailable for absorption in the intestinal tract. Bifidobacteria comprise a large fr action of the normal gut flora, are thought to provide many probiotic effec ts and are increasingly used in fermented dairy products. These qualities t argeted bifidobacteria for studies to determine if various strains of heat- killed bifidobacteria can bind affatoxin B-1 (AFB(1)) in vitro. The AFB(1) binding affinities of various strains of bifidobacteria, Staphylococcus aur eus, and Escherichia coli were quantitated utilizing enzyme-linked immunoso rbent and [H-3]AFB(1) binding assays. The bacteria analyzed were found to b ind significant quantities of AFB(1) ranging from 25% to nearly 60% of the added toxin. The data also suggest that there are reproducible strain diffe rences in AFB(1), binding capacity.