The "hidden pattern" in the mouth that may indicate colorectal cancer risk

The discovery is part of the study “Signatures of microbial transmission from mouth to gut enable robust and non-invasive diagnosis of gastrointestinal cancers”, published in the scientific journal Cell Host & Microbe.

The researchers' proposal is to understand whether the analysis of microorganisms in the mouth can function as a kind of “window” for changes that occur in the digestive system, paving the way for less invasive forms of assessment.

What can saliva reveal about colorectal cancer?

The central point of the research is the relationship between the bacteria found in the mouth and those present in the intestine.

Jihyun Kim, a biologist at Yonsei University, in South Korea, and one of the authors of the work, explained to Science Alert that several microorganisms associated with the oral cavity can also reach the intestinal tract.

“Many species of microorganisms associated with the mouth are also present in the intestine and that is where they can really thrive,” he said.

For scientists, the presence and distribution of these bacteria can form patterns that help differentiate people with certain types of gastrointestinal cancer.

“The presence of oral-associated bacteria in the gut of cancer patients was not entirely unexpected,” explained Sun Ha Jee, an epidemiologist at Yonsei University.

Research seeks less invasive tests

In addition to investigating the relationship between the oral microbiome and gastrointestinal tumors, the study seeks to advance the development of detection methods that are simpler for patients.

The possibility considered by the researchers is that, in the future, an oral sample could help identify changes associated with cancers of the digestive system or indicate people at greater risk of developing colorectal cancer.

This does not mean, however, that a saliva test can now replace existing diagnostic methods.

The researchers themselves highlight that further studies are still needed before this type of analysis can be reliably applied in clinical practice.

Mouth health also deserves attention

While the use of the oral microbiome to detect cancer is still in the research phase, experts reinforce the importance of oral health care.

The discovery draws attention precisely to the connection between the microorganisms present in the mouth and those capable of reaching the intestine, expanding scientific interest in the relationship between different parts of the organism.

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