Oral bacteria are found in 50% of colorectal cancer tumors

Researchers found bacterial strains commonly found in the mouth in about half of the colorectal tumors examined. This subtype they identified is noteworthy because it appears to protect tumor cells from anticancer drugs.

Experts describe the researchers' findings published in academic journals as follows: Naturecould help scientists develop new countermeasures colorectal cancer.

“Most interestingly, this suggests that targeting these specific bacteria in cancer could be used as another weapon against cancer during treatment.” Dr. Christopher D. Johnstonsaid study co-lead author and assistant professor at Fred Hutchinson Cancer Center. health.

This study was conducted at a time when cases of colorectal cancer are on the rise. is rising at an alarming rate Between 1995 and 2019, diagnoses among people in this age group jumped from 11% to 20%. The American Cancer Society predicts that colorectal cancer will kill more than 53,000 people in 2024, making it the second leading cause of cancer death in the United States.

Scientists know about the potential link between colorectal cancer and oral bacteria. Fusobacterium nucleatumthe cause periodontal diseasefor over 10 years.

Previous studies have shown that people with high amounts of bacteria in colorectal tumors have a poor prognosis, and that treating bacteria with antibiotics suppresses tumor growth in mice. It has been suggested that removal may also improve cancer.

The study also revealed certain aspects of how this bacterium works. Bacteria attach themselves to colorectal cancer as it spreads, and appear to be able to invade and change cancer cells in ways that may help the cancer grow.

For this study, the research team wanted to dig into specific points. Fusobacterium nucleatum Subtypes associated with colorectal cancer.

According to Johnston, Fusobacterium nucleatum Strains associated with colorectal cancer are of great importance because each can have unique effects on the cancer. “We set out to understand what makes these tumor-homing bacteria genetically distinct and special,” he said.

To do this, Johnson and his colleagues Fusobacterium nucleatum More than 200 patients with colorectal tumors were included.

they discovered it Fusbobacterium nucleatum It dominates the microbiome within some patients' tumors.They also found more abundant subtypes Crucian carp C2 It is present in approximately half of the tissue samples examined. Additionally, approximately 30% of stool samples collected from colorectal cancer patients Fna C2.

Genetic analysis also revealed how this subtype is able to survive far from the mouth. Scientists have discovered that it has certain properties that allow it to travel to the lower intestines and withstand stomach acid without dying.

“We have identified specific clades associated with: [colorectal cancer]And that's important in terms of treatment and prevention,” Johnston said.

Dr. Michael Whitesaid an assistant professor of colorectal surgery at the University of Texas MD Anderson Cancer Center, who was not involved in the study. health It is thought that this variant may even cause cancer formation.

“While this subtype of bacteria is normal in the oral cavity, it is not routinely found in the colon of healthy people,” he said. “This has led to the hypothesis that these bacteria may be involved in the development of colorectal cancer, as these bacterial species are regularly found only in the colon where malignant tumors have developed. I did.”

Professor White said scientists were just beginning to consider how this information could benefit patients.

he and his colleagues chemical treatment clear Fusbacterium nucleatum In rectal cancer, he said.

The bacteria themselves may also fight cancer cells.

Researchers have shown that this subtype can easily invade cancer cells, making it possible to genetically engineer bacteria to deliver anti-cancer drugs directly to tumors. This method would involve a version of the bacteria that cannot cause disease but can invade colorectal tumors.

The new findings could also prompt new screening programs, Johnston said.

“Identification of the specific bacterial types present in these tumors provides a pathway to screen high-risk populations for these bacteria and design minimally invasive screening kits for early detection of colorectal cancer.” was held,” Johnston said.