Isothiocyanates contained in wasabi destroy several strains of bacteria, yeast and mold. It is believed that the wasabi plant was first introduced due to its antimicrobial properties. Wasabi had to protect people from poisoning after eating raw fish.
Several scientific studies (Ono, 1998 and Shin, Lee, 1999) have shown that 6-MITC from wasabi extracts has strong antibacterial properties against Staphylococcus aureus and E. coli bacteria.
Isothiocyanates have shown inhibitory activity against Streptococcus mutans, a bacterium responsible for oral cavity losses (Masuda, 2000).
A biomassically important bacterium that inhibits ITC is Helicobacter pylori (Masuda, 2001, Shin, 2004, Haristoy, 2005). This bacterium is responsible for stomach ulcers and gastric cancer associated with them. The extracts from the wasabi kill the bacteria, even if it got into the cells surrounding the stomach.