- A new study looks into the differences in gut bacteria between people with and without colorectal cancer.
- Scientists found cancer patients to have a virus-infected bacterium that healthy people typically don’t have.
- An oncologist explains what the findings mean for future screening and prevention protocols.
While knowing the number-one sign of colon cancer may go a long way in getting a diagnosis early (which is so important), what’s inside your gut may also have some clues. That’s the takeaway from a new study that looks more closely at how gut bacteria—specifically, viruses found within gut bacteria—may increase colon cancer risk.
Meet the Expert: Michael Chuong, M.D., radiation oncologist at Miami Cancer Institute, part of Baptist Health South Florida.
Colorectal cancer (CRC) is the world’s third most common cancer and the second leading cause of cancer-related deaths worldwide, per the World Health Organization (WHO). According to the study, published in Communications Medicine, one of its main characteristics and, therefore, potential causes is dysbiosis, an imbalance in the gut microbiome or community of bacteria and viruses that live in the intestines.
The thing is: The human gut microbiome is so vast and complex that it’s difficult to pinpoint exactly which changes or imbalances are most harmful. So, for this study, researchers zeroed in on a common bacterium found in both healthy people and those with colorectal cancer—Bacteroides fragilis—to see if there were any notable differences in the bacteria that may lead to a better understanding of the disease.
Researchers first studied bacteria taken from patients with and without colorectal cancer and looked closely at their genetic makeup. In colon cancer patients, they discovered two previously unknown viruses within Bacteroides fragilis. Researchers then checked stool samples from hundreds of people with and without colorectal cancer to see if the same viruses were present.
“These viruses were found much more often in people with colorectal cancer than in people without it,” explains Michael Chuong, M.D., radiation oncologist at Miami Cancer Institute, part of Baptist Health South Florida. In fact, they found that people with colorectal cancer were almost twice as likely to have these infected bacteria.
Importantly, Dr. Chuong notes that the findings do not indicate that viruses, in general, cause colon cancer. But the discovery is still important. “The viruses may change how the bacteria behave,” Dr. Chuong says. “While we don’t yet know if they directly cause cancer, their presence could help doctors identify people at higher risk.” However, research is still in its early stages, and more needs to be done before this can become a mainstream part of treatment or prevention methods.
How to lower your chances of colon cancer
The disease is linked to controllable lifestyle factors that you should consider to keep yourself healthy, especially if you have a family history of cancer. According to Dr. Chuong, those may include:
- Getting regular screenings (colonoscopy or stool tests) starting at the recommended age
- Eating a diet high in fiber (fruits, vegetables, whole grains)
- Limiting red and processed meats
- Exercising regularly
- Maintaining a healthy weight
- Avoiding smoking
- Limiting alcohol
The bottom line
“This study suggests that the interaction between bacteria and viruses in the gut may play a role in the risk of colorectal cancer,” says Dr. Chuong. “In the future, testing for these viruses in stool samples could potentially help detect cancer earlier or improve screening tests. However, more research is needed before this becomes part of routine care.”
Read the full article here