A pathobiont is an organism that is native to the host's microbiome that under certain environmental or genetic changes can become pathogenic and induce disease.
[2] The term was originally coined in 2008 by Sarkis Mazmanian to describe Helicobacter hepaticus and its ability to cause colitis under certain environmental conditions.
The main argument against using the term is that some bacteria labelled as pathobionts also exhibit beneficial effects to hosts under normal conditions.
[1] Arguers against the term state all bacteria have metabolism that are environmentally dependent, and even symbionts have been shown to exhibit deleterious clinical effects under certain conditions.
[1] The argument has led to the development of a proposed term, pathogenic potential, to describe a microbe's ability to cause disease.