Detoxification of aflatoxin b1 by Lactobacillus rhamnosus in a simulated model of the human digestive system

According to the FAO annual report, 10 percent of the world's food products are contaminated with fungal toxins, among which aflatoxins have the most contribution as compared to others. This research was aimed to assess the ability of Lactobacillus rhamnosus strain GG in the reduction of aflatoxin B1 (AFB1) in a simulated human gastrointestinal tract containing sterilized milk.   For this purpose, the bacterial count and aflatoxin concentration were adjusted to 1×1010 cfu/ml and 5 ppm, respectively, where artificial gastrointestinal tract discharges were inoculated in the simulated environment. In this study 6 treatment groups were assessed in the presence and absence of bacteria, sterilized milk, and gastrointestinal juice suspension. The concentration of residual aflatoxin was determined using high-performance liquid chromatography (HPLC) and purification by Immunoaffinity column.   The reduction of aflatoxin B1 at all treatments was determined using HPLC with a detection limit of 0.25 mg/ml and a quantification limit of 0.75 mg/ml. The mycotoxin recovery rate was between 89% and 94% for AFB1. The aflatoxin B1 calibration curve with a correlation coefficient of 0.95 was linear in the concentration range of 1 to 10 ng/ml. The highest and lowest average removal percentage of aflatoxin B1 was observed for 5 and 1 treatments (58.8 ± 0.018 and 13.86 ± 0.017) respectively, where a significant difference in removal percentage was observed among six treatment groups.   The results indicated that beside L. rhamnosus strain GG, gastric and small intestine juices are suitable to eliminate or reduce aflatoxin B1, as well.