Allicin is the very potent medicinal agent in garlic, effective against bacteria, viruses, molds, yeasts and other organisms. Newer discoveries have extended the list of garlic compounds to more than four hundred, with at least 30 of them having known medicinal properties. Most of garlic's medicinal constituents result from the breakdown of allicin. Allicin is highly unstable, however, and it degrades almost completely within 24 hours. It also breaks down completely within 20 minutes at higher temperatures, such as in cooking. The degradation, however, produces new components with a wide variety of medicinal effects. Allicin and its breakdown products all contain the element sulfur in a form that readily interacts with important enzyme systems.

*Bacteria transmitted through to hatching eggs. May cause death in embryos at 21 days (pipped and unpipped).

Diseases that humans can get, directly or indirectly, from chickens can be broken down into four categories: environmental, parasitic, zoonotic and toxic. It is possible for humans to contract some infections from the same sources as chickens, the result of environmental exposure rather than inter-species contagion. Most human disease caused by the poultry environment is mycoses or fungal infections. Parasitic diseases are among the most unlikely diseases a human can get from a chicken.