Scientists have identified a distinct microbial signature in the gut microbiome that is strongly associated with colorectal cancer, a discovery that could pave the way for earlier diagnoses and more effective prevention strategies. The findings, published in Cell Host & Microbe, suggest that these microbial changes may appear early in the development of the disease.
The study analyzed 27 existing studies, encompassing nearly 7,000 gut microbiome sequencing profiles, to identify a cancer-associated microbial pattern that remained consistent across different age groups and populations. Researchers found that the microbes detected in stool samples mirrored those found directly within colorectal tumors. This suggests that the detection of these specific microbes could potentially signal the presence of early-stage tumors.
Colorectal cancer is a growing concern, particularly among younger adults, where it has surpassed breast and brain cancer as a leading cause of cancer death. The study also uncovered a link between diet and the observed microbiome pattern. Specifically, a lower intake of dietary fiber was associated with a stronger cancer-associated microbiome signature, while a higher fiber intake correlated with a reduction in this pattern.
Experts note that while diet is not the sole factor, it plays a significant role in colorectal cancer risk. The consumption of ultra-processed foods has been implicated in the rise of diagnoses among younger populations. These foods can disrupt the gut microbiome and contribute to inflammation, according to Dr. Christine Molmenti, an associate professor and cancer epidemiologist at Northwell Health.
Previous research had indicated differences in gut health between individuals with and without colorectal cancer, but these studies were often limited in scope. The current research's advantage lies in its large-scale analysis and the application of machine learning algorithms to distinguish cancer-related microbiomes from non-cancerous ones. This advanced approach enabled the identification of a reproducible gut microbiome signature in individuals with both early- and late-onset colorectal cancer.
While the findings represent a significant step forward in understanding the gut microbiome's role in colorectal cancer, researchers emphasize that this is not yet a diagnostic test. Instead, it serves as a crucial advancement toward developing microbiome-based detection and prevention methods.