Preliminary results from test tube and animal studies suggest that cinnamon oil and cinnamon extract have anti-fungal, anti-bacterial, and anti-parasitic properties. For example, cinnamon has been found to be active against Candida albicans, the fungus responsible for vaginal yeast infections and thrush (oral yeast infection), Helicobacter pylori (the bacteria that causes stomach ulcers), and even head lice.
An incredible experiment in the journal of Food Science for 1974 demonstrated the power of cinnamon over most yeasts and fungi. Slices of white, raisin, rye and whole wheat breads, manufactured without the usual mold inhibitors, were subjected to various aflatoxins, a group of toxic molds so dangerous that they can cause liver cancer and kill humans and animals alike and often occur in food. The toxic molds grew vigorously on all of the other breads, except for the raisin bread where growth was described as being "scant or not visible at all." In trying to identify whether it was the raisins or cinnamon responsible for this, food scientists discovered that as little as 2% or 20 mg. of the spice per ml of a yeast-extract and sucrose broth inhibited 97 -99 per cent of these molds.