Protists as determinants of the One Health framework.

One Health connects three main health elements: humans, animals, and the environment. Protists influence all three, but their role in the overall One Health framework has been widely overlooked. Here, we highlight the key characteristics that make protists integral to the One Health framework and provide examples on the negative and positive effects of protists on each element. Most importantly, we emphasize how protists connect all One Health elements. Finally, we discuss how protists can be leveraged to enhance One Health. In conclusion, the vast diversity (phylogenetical, functional, and morphological) of protists is key in shaping One Health and can be targeted to improve individual One Health elements and their connections.