Heat-stabilized defatted rice bran (HDRB) is fermented with yeast to afford a food product having superior prebiotic for probiotic properties. Fermentation of HDRB with yeast yields a prebiotic composition that can promote the growth and/or activity of beneficial intestinal bacteria (probiotic) when consumed by an animal or human. The prebiotic and/or probiotic compositions can afford substances having desirable health effects when consumed. The yeast fermented, and the probiotic fermented extracts and residues will have several nutraceutical compounds including protein, phenolics, phytic acid, arabinose, bioactive isoflavones, dietary fibers and several others that will have health benefits. Inclusion of legumes during fermentation can synergistically enhance the bioactivities of HDRB. HDRB can be a source of growth medium for yeast/mold/microorganisms.