In vitro evaluation of the efficacy of lactobacilli and yeasts in reducing bioavailability of inorganic arsenic

This study evaluates the potential of strains of Lactobacillus and Saccharomyces cerevisiae to reduce inorganic arsenic [iAs, As(III)+As(V)] bioavailability. Removal of iAs from aqueous solutions by these strains was evaluated and their effect on iAs bioaccessibility was analyzed by in vitro gastrointestinal digestion. The effect of the strains on iAs absorption was also tested, using intestinal cells. The results showed that iAs removal by the yeast strains was low (<10%). In contrast, some lactobacilli substantially reduced As(V) concentration in solution (25–40%) but only when the concentration of phosphate was ≤1 mM. Both microorganisms were able to reduce cellular transport of iAs added as aqueous solution (11–58%). Moreover, a strain of Lactobacillus plantarum reduced cellular transport of iAs from rice by up to 45%. We conclude that, in vitro, some lactobacilli and yeasts could reduce intestinal absorption of inorganic As present in water and food, and consequently reduce its bioavailability.