This research demonstrates that different strains of the same medicinal mushroom species can have very different properties and health benefits. The study focused on three types of bracket fungi traditionally used in European medicine and found that their ability to fight bacteria and other fungi varies significantly depending on which specific strain is used. This has important implications for both traditional medicine and modern drug development. Impacts on everyday life: • Better quality control for medicinal mushroom products through proper strain selection • More effective natural antimicrobial treatments by using optimal fungal strains • Improved understanding of how geographic origin and growing conditions affect medicinal properties • More reliable identification of beneficial mushroom species for foraging and cultivation • Enhanced potential for developing new antibiotics from mushroom compounds