Called a big feat in microbial research, researchers have decoded all the bacterial genes found in the human gut-a total of 160 species.
The discovery has far-reaching implications for human health and well being, and could even be used to predict chronic intestinal illnesses, from ulcers to cancer, reports the Independent.
The study decoded the DNA sequence of the many thousands of genes used by the vast number of bacteria, which take up permanent residence inside the human intestines.
It found that about 1,000 different species of microbe can live in the healthy human gut and that each person on average has about 160 species living inside them at any one time - and most of these species are common to different people.
Studying gut bacteria has been difficult, because many are unable to be grown outside of their natural habitat, and that is why the scientists believe their findings will shed light on a little-understood or discussed aspect of human biology.
It is estimated that a healthy human gut contains about 100 trillion microbial cells, about 10 times as many cells as there are in the human body.
Yet not much is known about what these bacteria do to maintain health and well-being, said Jeroen Raes of Vrije University in Brussels.