Indigenous microflora is defined as the community of micro-organisms that live on or in another living organism or in a particular environment. These micro-organisms include bacteria, algae and fungi.
Healthy animal tissue, such as blood and muscle, is normally free of micro-organisms, but there are many places on and within the healthy body where micro-organisms are always present, including the skin, the mucus membranes and the intestinal tract. This normal flora, also called "indigenous microbiota," is not generally pathogenic in nature and, in most cases, provides benefits to the host. For the most part, the relationship between the host and its flora can be described as "mutualistic." While the host provides the bacteria with a constant supply of nutrients and protection from the environment, the bacteria aid the host's digestive processes and help protect the host from being infected by pathogenic microbes.
The microbes that inhabit the average healthy human body represent a huge number of cells. The human body is made up of roughly 10 trillion cells, but according to Discover magazine, the number of bacterial cells the body plays host to is closer to 100 trillion or ten times as many. However, because bacterial cells are so tiny, that entire microbial population would only fill a half-gallon jug.