Gut bacteria may be linked with the onset of colorectal lesions and cancers, finds a study.

The research led by a team at University Medical Center Groningen in the Netherlands identified significant variations in the gut microbiome of individuals who developed precancerous colonic lesions.

The findings, presented at the United European Gastroenterology (UEG) Week 2023 held in Denmark, opens promising new avenues for enhancing the detection and prevention of colorectal cancer.

“The connection between the gut microbiome and pre-cancerous lesions has been underexplored, leaving uncertainty about whether gut bacteria can predict the future onset of colorectal cancer,” said lead author Ranko Gacesa, from the University Medical Center Groningen.

“Our findings suggest that the microbiome could act as a valuable tool to improve existing tests, advancing early detection methods for pre-cancerous lesions and colorectal cancer,” Gacesa added.

Colorectal cancer is a significant global health concern. It typically develops from precancerous lesions within the gut, making the removal of these lesions an effective strategy for preventing colorectal cancer.

However, existing non-invasive detection methods, such as the faecal immunochemical test, produce a high number of false positives, leading to unnecessary colonoscopies.

The study, involving 8,208 participants, identified all recorded cases of colonic biopsies from the last five decades. Researchers analysed the function and composition of the gut microbiomes of individuals who developed precancerous colorectal lesions before faecal sampling between 2000 and 2015, as well as those who developed lesions after faecal sampling between 2015 and 2022.

These groups were then compared with individuals with normal colonoscopy findings and the general population.

To gain a deeper insight into the gut microbiome’s role, researchers are also examining specific bacterial strains and their functions within the gut by reconstructing their genomes from metagenomic data.

The results revealed that individuals who developed colonic lesions after faecal sampling exhibited increased diversity in their gut microbiome compared with those who did not develop lesions.

Moreover, the composition and function of the microbiome differed among individuals with pre-existing or future lesions and varied based on the type of lesion.

Notably, bacterial species from the family of Lachnospiraceae and the genera Roseburia and Eubacterium were linked with the future development of lesions.