A variety of bacterial species in the human gut, generally categorized as probiotic bacteria, promote general gastrointestinal health, and are positively correlated with broader physical and mental wellbeing1-3. Many different lactic acid bacteria (LAB) species are probiotic and are typically grown in culture using traditional media formulations to meet their complex nutritional demands. Traditional media for propagation of LAB (e.g. deMan, Rogosa, and Sharpe (MRS) and M17) include complex undefined animal derived components such as beef extracts, casein hydrolysates and porcine hydrolysates. There is a growing demand and need for production of probiotics that are not reliant on animal derived components. This study shows the soy protein hydrolysate, HSP-A, can replace all animal derived components in MRS and M17 formulations to support the growth of Lactobacillus acidophilus ATCC 314 and Lactococcus lactis ATCC 11454. These results show HSP-A is effective ingredient for formulating animal derived component free (ADCF) media for production of probiotic bacteria. Figure