After examining the impact of exercise on the gut microbiome of patients with cancer and reporting a positive association, researchers discovered that regular physical activity may extend the survival of patients with colorectal cancer, according to a new study published by Himbert et al in the American Journal of Cancer Research. Researchers also found that physical activity was beneficial to patients who had cancer and were classified as obese.
The findings are an important step in understanding how a healthy gut may improve patient outcomes, and represented the first study investigating the effects of exercise on the outcomes of patients with colorectal cancer.
The researchers found that regular physical activity may have been a factor contributing to a healthy gut microbiome, while also reducing inflammation. These findings were reported in patients independent of their body mass index (BMI)—even in those classified as severely overweight or obese.
“A patient who is active has a more diverse microbiome and lower abundances of colorectal cancer–promoting bacteria, and higher amounts of bacteria that protect against colorectal cancer,” said lead study author Caroline Himbert, PhD, a postdoctoral fellow in the Division of Cancer Population Science at the Huntsman Cancer Institute as well as in the Department of Population Health Sciences at the University of Utah School of Medicine. “Our study suggests that nobody needs to be an athlete to get the benefits. It can be easy activities. Just staying active is very beneficial,” Dr. Himbert highlighted
Adults need 150 minutes of moderate exercise per week, according to the U.S. Centers for Disease Control and Prevention, or roughly 20 minutes of brisk walking or light jogging per day.
“Inflammation is a key process that drives colorectal cancer. We know a high BMI causes inflammation around the body,” said Cornelia Ulrich, PhD, MS, the Jon M. and Karen Huntsman Presidential Professor of Cancer Research in the Department of Population Health Sciences, as well as Chief Scientific Officer and Executive Director of the Comprehensive Cancer Center at the Huntsman Cancer Institute at the University of Utah School of Medicine. “Obesity is on the verge of becoming the number one cause of cancer in the United States, surpassing smoking. More than 13 cancers are linked to obesity. It’s important [that] we understand [how] moderate exercise can help [patients with] colorectal cancer reduce inflammation, improve their gut health, and live longer—even if they are overweight or obese,” Dr. Ulrich emphasized.
Colorectal cancer is the third most common cancer in the United States, with 106,180 new cases of colon cancer and 44,850 new cases of rectal cancer in 2022, according to the American Cancer Society. Having high levels of inflammation—common in individuals with higher BMIs or in those who are not physically active—may increase a person’s risk of developing colon cancer.
“If you reduce your BMI, you have lower levels of inflammation. If you have lower inflammation, your risk of death is reduced,” stressed Jennifer Ose, PhD, MS, MPH, an investigator in the Division of Cancer Population Science at the Huntsman Cancer Institute and Research Assistant Professor in the Department of Population Health Sciences at the University of Utah School of Medicine.
The researchers recommended that people who are at average risk for colorectal cancer should start regular screenings when aged 45 years, with either a colonoscopy or fecal immunochemical test.
The results of the study indicated that physical activity may offset gut microbiome dysbiosis as a result of obesity, and that alterations in gut microbiota may further contribute mechanistically to the energy balance-colorectal cancer link and impact clinical outcomes.
Disclosure: The research in this study was supported by grants from the National Cancer Institute and Huntsman Cancer Foundation. For full disclosures of the study authors, visit ncbi.nlm.nih.gov.
