August 19, 2026
A new review published in Trends in Immunology, synthesizes current evidence that the microbiome is an important mediator of exercise-driven benefits to the immune system, identifies challenges and limitations in the field, and lays out questions that still need to be addressed.
Written by Marlies Meisel, associate professor of immunology, and recent Program in Microbiology and Immunology graduate Catherine Phelps, the article discusses how exercise shifts the gut microbiome—both in terms of composition and function—in mice and humans and how these shifts influence immune function in health and disease contexts, including cancer, autoimmunity, obesity, and diabetes.
“We propose that the compositionally and functionally distinct exercise-primed microbiome represents an untapped reservoir of immunomodulatory and druggable microbial metabolites that could be harnessed through exercise prescriptions, FMT [fecal microbiota transplant], prebiotics, probiotics, or metabolite-based therapies,” they write.
In a recent Cell study, Meisel, Phelps and their team showed that exercise-driven changes to the gut microbiome boosts antitumor immunity and promotes immunotherapy efficacy via a compound called formate. However, this is one of few studies that have identified the mechanisms by which the microbiome influences the immune system, highlighting a need for more mechanistic studies.
See also: New Review Outlines How Exercise Reshapes the Immune System
Other considerations to advance this field towards the goal of exercised-based therapeutic strategies include analyzing the functions of microbiome rather than simply which bacteria are present, considering non-bacterial components of the microbiome such as fungi and protists, and the development of standardized exercise interventions and measurements to allow better comparisons across studies.