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