Biofilms were grown on preconditioned voice prostheses with biosurfactants obtained from probiotic bacteria Lactococcus lactis 53 and Streptococcus thermophilus A in an artificial throat model. Both biosurfactants greatly reduced microbial numbers on prostheses and also induced a decrease in the airflow resistance that occurs on voice prostheses after biofilm formation. This study presents a promising strategy for prolonging the lifespan of voice prostheses.