Abstract: Rats with continuous low-dose intake of aflatoxin B1 (AFB1) were supplemented daily with live and inactivated suspensions of Lactobacillus rhamnosus and its cell-free culture supernatant at different concentrations, separately. To evaluate whether and how effectively Lactobacillus rhamnosus could reduce AFB1 in rats, serum biochemical and immune indicators were measured. All animals except those in the control group were given AFB1 at a dose of 50 μg/kg and administered intragastrically with Lactobacillus rhamnosus at a volume of 0.5 mL. The effects of Lactobacillus rhamnosus and its cell-free culture supernatant at different concentrations on the growth and immune function of rats were evaluated by determining body mass, serum cytokine levels and immunoglobulin (Ig) levels. The results showed that live Lactobacillus rhamnosus had a good adsorption capacity for AFB1 in rats and its effects varied significantly with its concentration. Live Lactobacillus rhamnosus at high dose had the best effect on maintaining the health status, liver function and immune function of rats. Although inactivated Lactobacillus rhamnosus also had certain adsorption capacity for AFB1 and significantly maintained aspartate aminotransferase (AST) activity, as well as IgM and IgG in rats, it was ineffective for cytokine stabilization. In contrast, the low concentration cell-free culture supernatant of Lactobacillus rhamnosus had a poor adsorption effect toward AFB1 in rats, which was effective only at high concentration.

Key words: Lactobacillus rhamnosus, aflatoxin B1, adsorption, immune system