Penicillin

The ancient Egyptians used to treat some patients by eating rotting bread. No one understood why until 1928, 5,000 years later, when modern science discovered by Alexander Fleming that penicillin had a great antibiotic effect on bacteria,

What is the relationship of bread to the subject?

If bread is left until the rot of a fungus called "Penicillium - Penicillium" is appeared on the bread’s face, which is derived penicillin, was the most famous antibiotic used so far in the treatment of some types of bacteria by the Egyptians 5000 years ago!