It has happened to everyone who has ever bought bread; a week later, you notice some green fuzz on one end of the bread. Your bread has grown mold on it. What do you do? The frugal side of you says to discard the moldy portion, and save the rest. The cautious side wonder, is it really safe to eat the rest of this?
The risks associated with consuming moldy bread have a long history; ergotamine, a mycotoxin found in rye bread, is thought to be responsible for the "bewitching" of the girls in the Salem Witch Trial. Ergotamine is one of the active components in LSD, and exposure can cause hallucinations and a number of other symptoms, including seizures and spasms. While it is unlikely that you run any risk of tripping from eating moldy bread, there may be some other risks associated with the consumption of your loaf of bread.
Dr. Ruth Etzel published in the Journal of the American Medical Association that the grain supply in America is commonly contaminated with mycotoxins. Exposure to these mycotoxins has been linked to a variety of diseases in humans. While care is taken to control mycotoxin contamination in grains, a small fraction is permissible. If your diet is heavy in grains over a sustained period of time, you run the risk of exposure, and cumulatively you may be exposed to more than you would like to be.
Furthermore, if you are struggling with any sort of pathogenic fungal problem, consuming grains does little but add fuel to the fire. Sugar is fungi's food of choice; grains immediately convert to glucose in the digestive process, providing fungi with their preferred source of nourishment.
For these reasons, Phase 1 seeks to limit grains in the diet. By doing this, you will limit exposure to mycotoxins and deny pathogenic yeasts their preferred food choice.
So, while the moldy patch on your bread may not be the biggest concern, it may be a good choice to get rid of the loaf of bread altogether.