Method for preparing immunomodulator and immunomodulator

Disclosed is a method for easily obtaining an immunomodulator that uses Lactobacillus cells as a starting material and that can obtain an active component with immunomodulatory activity easily and moreover in a form that is easily used in medicines and functional foods. Also disclosed is an immunomodulator obtained by means of said method. The preparation method involves a step for shaking a mixture of Lactobacillus cells and a surfactant solution and a step for separating and collecting an extract from the shaken mixture; and particularly involves a step for crushing the Lactobacillus cells, a step for concentrating the crushed bacterial cells in order to obtain a fraction comprising at least the cell membrane components of the crushed bacterial cells, a step for shaking a mixture of the obtained concentrate and the surfactant solution, and a step for separating and collecting an extract from the obtained shaken mixture.