Provided herein are novel Lactobacillus fermentum strains, NRRL B-67059 or NRRL B-67060, compositions containing the NRRL B-67059 or NRRL B-67060 strains, and fermented dairy products and bioactive compounds prepared using the NRRL B-67059 or NRRL B-67060 strains. Also provided are methods of modulating the immune system of a subject.