The complex and unique system of bacteria and viruses—or bacteriophages—the viruses that infect those bacteria, all in the human gut, has implications on the overall health of humans, as well as the incidence of certain diseases.
As more and more research is being done on the micro-biosphere in the intestines of humans, it becomes more clear how much of a role microorganisms play in our health. Explorations of the bacteria in the gut have long been underway and are understood to some degree. New research is finding out that viruses in the gut, too, in combination with bacteria, have an effect on human health.
As reported in PNAS, nearly 50 billion bases of DNA were collected in the stools of 12 individuals. Thousands of likely distinct viruses were assembled and all but one type were bacteriophages (the other was a human papillomavirus found in a single individual). Bacteriophages are responsible for the toxic effects of many bacteria, but their role in the human microbiome has only recently started to be studied. As noted, "This method opens a whole new world of 'diversity-generating' biology to discover what these clearly important systems are actually doing,"