The Gut As an Immune Organ

Humans share the environment with huge numbers of microorganisms.According to Whitman et al. 4–6 x 1030 prokaryoticcells exist on earth.1 All animals ingest food and water for energy,while living in contact with a significant bacterial burden in nearlyevery environment. Food is usually clean in industrialized culturesbut may not be in non-industrialized parts of the world. Regardlessof the food source and/or processing, the gut processes the foodand water in our daily life for digestion and absorption. The gutalso functions as an immune organ to protect us from any ingested,potentially pathogenic bacteria.