In vitro Study of the Potential Protective Role of Lactobacillus Strains by Acrylamide Binding

Acrylamide is a chemical naturally formed in certain foods during processing and/or cooking at high temperatures. Scientific studies have indicated that significant dietary exposure to acrylamide poses a risk for several types of cancer and may have harmful effects to the nervous system in humans. Hence, methods that can contribute to reduce acrylamide exposure in foods are needed. Considering that specific lactic acid bacteria are able to remove a variety of foodborne mutagens, namely heterocyclic amines, lead, cadmium and aflatoxin B₁ by a binding mechanism, the aim of the present study was to assess the ability of fourteen lactic acid strains to remove acrylamide in vitro. Acrylamide binding ability ranged from 11.89 to 29.12%, and it was found to be both concentration‐ and strain‐dependent. Lactobacillus reuteri Northern Regional Research Laboratory 14171 (USDA‐ARS) and Lactobacillus casei Shirota were the most efficient binders (24.01 and 24.95%, respectively) after 12 h of incubation using an acrylamide concentration of 5 μg/mL. Acrylamide binding was also pH‐dependent, and the bacterial–toxin complex exhibited high stability assessed by repeated washings. The results of this work proposes for the first time the acrylamide binding ability in vitro of selected lactic acid bacteria, which suggest their potential for detoxification of the food contaminant acrylamide. PRACTICAL APPLICATIONS: All bacteria tested proved capable to bind acrylamide efficiently and rapidly in phosphate buffer saline; hence, these bacteria could be an effective decontamination mechanism against foodborne acrylamide along the gastrointestinal tract. It is reasonable to believe that during the first contact of acrylamide‐contaminated food with lactic acid bacteria in the mouth, the place where digestion starts and the pH is favorable for the toxin–bacteria interaction, a portion of acrylamide may be bound by the bacteria. Moreover, as both toxin and bacteria navigate through the digestive tract, the variations in pH may cause mutagen binding at different extents until it reaches the small intestine (alkaline pH), the site where absorption of food components is the highest, and the pH value is favorable. Therefore, this kind of bacteria could play a protective role by reducing the bioavailability of foodborne acrylamide.