The Genetic Gymnastics of Our Indigenous Microbes

Bacteria indigenous to the human body are numerous and varied and dwell in multiple niches in skin and on mucosal surfaces; many niches are persistently colonized by one or more species, often for the host's life span. Such persistence implies an equilibrium in which the biologic cost of the colonization to the host is low.1 The colonizing organisms occupy all available niches, compete for nutrients and favored locations, and participate in communal activities, such as waste management and genetic exchange.Colonization of the stomach by Helicobacter pylori is an exception to these generalities because it can last for decades in . . .