Sheila Rao was a NOMIS–Salk Fellow at the Salk Institute for Biological Studies (La Jolla, US).

Rao received her PhD in immunology in 2013 from the University of Pennsylvania in Philadelphia. There, she worked on innate immune cell receptor signaling to identify the mechanisms by which the immune system recognizes foreign microbes.

As a NOMIS–Salk Fellow, Rao investigated host-microbe interactions in the context of gastrointestinal infection, using the bacterium Salmonella as a model. She discovered that Salmonella, a microbe that causes disease, has actually evolved a strategy to promote host health during infection. Salmonella does this by manipulating signaling from the gut to the brain, which results in a decreased host anorexic (lack of appetite) response and improved host metabolic function. By inhibiting host anorexia, Salmonella improves the health of the host, which results in increased fitness of the microbe. Thus, by promoting host health, Salmonella ensures its own survival. This work helps to clarify the role of sickness-induced behaviors (like anorexia) and demonstrates that microbes have evolved strategies to maintain or even improve health of their hosts. Investigating how we have co-evolved with microbes will enable us to learn more about our own physiology and to better understand how to promote health during disease as a therapeutic strategy. Rao, Janelle Ayres and colleagues published this work in the journal Cell in 2017.