Researchers have uncovered the impact of chemotherapy on the gut microbiome in patients with breast cancer, according to a recent study published by Otto-Dobos et al in Brain, Behavior, and Immunity.
Background
Chemotherapy is known to cause behavioral side effects, including cognitive decline. Notably, the gut microbiome communicates with the brain to affect behavior and cognition.
“Side effects of chemotherapy are common and may reduce quality of life, but these side effects can be dismissed as part of chemotherapy and therefore overlooked and undertreated,” explained senior study author Leah Pyter, PhD, Associate Professor of Psychiatry and Neuroscience at The Ohio State University Wexner Medical Center and College of Medicine, a researcher at the Institute for Behavioral Medicine Research, and a member of the Cancer Control Research Program at The Ohio State University Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC–James).
Study Methods and Results
In a longitudinal observational study, researchers examined whether chemotherapy-induced disruption of the gut microbiome might be associated with cognitive decline and circulating inflammatory signals using blood and cognitive measures collected from 77 patients with breast cancer prior to, during, and following chemotherapy.
The researchers discovered that chemotherapy promoted microbiome disruption and inflammation. These changes were linked to cognitive decline and inflammation. The patients who presented with cognitive impairment had unique chemotherapy-induced microbiome alterations.
“We found that patients treated with chemotherapy who showed decreases in cognitive performance also had reductions in the diversity of their gut microbiome,” Dr. Pyter emphasized.
This findings built on prior research in mouse models revealing that chemotherapy-induced shifts in the gut microbiome caused neurobiologic changes and behavioral side effects. The recent study indicated that an association between the gut microbiome and cognitive performance existed in humans as well.
Conclusions
“For the first time ever, our Intelligut study found that the gut microbiome has been implicated in cognitive side effects of chemotherapy in humans. The potential connection between the gut and the brain would allow us to create treatments for the gut to treat the brain,” highlighted Dr. Pyter. “We believe that gut microbiome–focused interventions, such as fecal microbial transplantation, may improve behavioral side effects of chemotherapy,” she continued.
The researchers are currently conducting studies exploring the gut microbiome’s impact on cancer treatment effectiveness and its role in reducing or increasing the risk of cancer.
“Chemotherapy is a very important tool for stopping many cancers, and side effects should not deter patients who would benefit from this type of therapy from pursuing it, but we know the side effects of some treatment regimens can be quite challenging for patients to complete,” underscored David Cohn, MD, Interim Chief Executive Officer of the OSUCCC–James. “It’s a careful tightrope of walking between effective cancer control and side effect management—and our team is working every day, in the hospital clinics and the lab, to develop ways to manage the side effects of disease treatment with an eye toward quality of life,” he concluded.
Disclosure: The research in this study was supported in part by the National Institutes of Health and The Ohio State University Wexner Medical Center. For full disclosures of the study authors, visit sciencedirect.com.