Aureobasidium (black yeast) culture medium (hereafter referred to as “Aureo culture medium”) and EF lactic acid bacteria were tested for their protective effect against Listeria monocytogenes, one of the causative organisms of food poisoning.

When mice were divided into three groups and infected with Listeria monocytogenes by administering the test substances, 71.4% of the Aureo culture medium-treated mice and 85.7% of the mice treated with the combination of Aureo culture medium and EF lactobacilli survived, while those treated with saline solution (PBS) were completely destroyed.

Based on these results, the combination of Aureo culture medium and EF lactobacilli was found to have immunostimulatory effects.