[Researcher Janelle] Ayres was running the experiment to determine what causes genetically identical mice to respond differently to the same pathogen.
Compared with mice that died from the infection, the mice that survived expressed lots of genes linked with metabolizing iron. This indicated to Ayres that iron might help the animals cope with the infection.
[T]he bacterium in the mice fed iron had accumulated mutations that tamped down expression of multiple genes for proteins in a virulence pathway, disabling its ability to cause disease. The bacteria, found in the colon, were, in essence, “just part of the [mice’s] microbiome now,” Ayres says.
The results, published in the summer of 2018, support a hypothesis Ayres posited years ago: that fighting infections doesn’t have to be all-out war. Instead of trying to obliterate pathogens that have invaded the body, she proposes, organisms may give them what they want and ultimately push them to evolve into something benign, lessening the damage done by the pathogen and the immune system. This phenomenon known as disease tolerance, is something that the body can do naturally by tapping into different physiological systems, such as metabolism, to prevent illness.
Read full, original post: Could Tolerating Disease Be Better than Fighting It?