Abstract: A method of controlling a biofilm comprises contacting the biofilm with probiotic species and contacting the biofilm with chemical disinfectant. The biofilm may be contacted with the probiotic species and the chemical disinfectant simultaneously or sequentially. The method provides a higher reduction in the amount of at least one microbial species in the biofilm, compared to a similar method applying only the chemical disinfectant. Furthermore, the method may provide an unexpected synergy between the probiotic species and the chemical disinfectant in controlling the biofilm.