Anethole is an essential oil in star anise which gives it a licorice flavor. It is effective against some types of bacteria. Data published in the February 2002 edition of Phytotherapy Research showed the anethole isolated from star anise protective against some micro organisms. Anethole can prevent the growth of Escherichia coli and Staphylococcus aureus. E. coli spread by contamination of food primarily affects the digestive system causing vomiting and diarrhea. Staphylococcus aureus found on food and some surfaces frequently infects the skin.