Tapping into symbiosis to advance human microbiome research

Gina R Lewin, Lily Khadempour 

In human microbiome research, the term commensal is often used to describe organisms that benefit their hosts. In ecology, where the term originates, a commensal organism has no impact on its host, whereas a mutualist organism benefits its host. While others have recognized this discrepancy in terminology use, old habits are hard to break, and the human microbiome community has continued in this vein. This is our call to action for the human microbiome community to use more precise terminology that appropriately reflects the impact that these microbes have on their hosts. We should use the terms commensal and mutualist when we know the effect on the host, and symbiont when we do not. By using the same terminology as ecologists, we will be able to make use of and contribute to the vast research in the field of symbiosis.