Time for a gut check.
Cases of colorectal cancer are on the rise, surpassing breast and brain cancer as the leading cause of cancer deaths among adults under 50.
But earlier diagnoses could soon be possible thanks to a recent discovery — in which scientists also confirmed that a single diet choice makes a major difference in your risk.
It’s long been suspected that our gut microbiomes are closely linked to colorectal cancer.
Now, a study published in Cell Host & Microbe has identified a strong microbial signature associated with colorectal cancer — one that appears to be consistent across different age groups and populations.
Researchers found that microbes — tiny organisms like bacteria, viruses and fungi that are too small for the naked eye to see — detected in poop samples reflect those found directly within colorectal tumors. Those cancer-associated could already be detected in early-stage tumors.
This suggest that microbial changes linked to cancer may appear early on, raising new questions about whether tumors alter the microbiome or whether microbiome changes help drive cancer development.
The study also found a connection between diet and the cancer-associated microbiome pattern.
Lower dietary fiber intake was linked to a stronger cancer-associated microbiome pattern, while higher fiber intake was associated with a reduction in that pattern.
While diet is not the only factor involved, it plays an important role in colorectal cancer risk, with higher consumption of ultra-processed foods linked to the rise in diagnoses among younger adults.
“Everything that we eat touches our colon, good or bad,” Dr. Christine Molmenti, an associate professor and cancer epidemiologist at Northwell Health, previously told The Post.
“Junk foods and ultra-processed foods can disrupt the microbiome,” Molmenti added. “They can lead to inflammation.”
Previous research has shown differences between the gut health of people with colorectal cancer and those without the disease, but these studies were much smaller, making it difficult to determine if the findings applied broadly.
This study analyzed 27 studies — comprising 6,779 publicly available gut microbiome sequencing profiles — to obtain more comprehensive data.
Another feature that advances the research was the use of machine learning algorithms to distinguish cancer from non-cancer microbiomes at a large scale.
This allowed the researchers to identify a gut microbiome signature that was reproduced across multiple people with both early- and late-onset colorectal cancer.
The findings could pave the way for future research into the gut microbiome-colorectal cancer connection, as well as microbiome-based detection and prevention strategies.
However, the researchers emphasized that the findings are not a diagnostic test yet, but rather a step toward better understanding how organisms in the gut may help advance cancer research and detection.
