ABSTRACT
The digestive system is a major portal of entry for bacteria, viruses, and parasites. Many infectious diseases occur through the ingestion of water and food, but it is important to keep in mind that the defenses of the digestive system are very strong and keep many infections from ever happening. Remember also that the mouth and large intestine are crowded with microorganisms that are part of the body’s normal flora (the microbiome), and the presence of this normal flora is part of the body’s defense against opportunistic infection.
