Gut Microbiome Variations May Predict Colorectal Lesions and Cancer

Recent research has identified significant variations in the gut microbiome of individuals who developed pre-cancerous colonic lesions, potentially establishing a link between gut bacteria and the onset of colorectal lesions and cancer. A new study, presented at UEG Week 2023, offers promising avenues for improving colorectal cancer detection and prevention.

The large-scale prospective study encompassed 8208 participants and utilized data from the Dutch Microbiome Project and the Dutch nationwide pathology database to uncover recorded cases of colonic biopsies spanning five decades. Researchers investigated the composition and function of the gut microbiomes in individuals who developed pre-cancerous colorectal lesions before fecal sampling between 2000 and 2015 (n=214) and those who developed lesions after fecal sampling between 2015 and 2022 (n=305). These groups were compared with individuals with normal colonoscopy findings (n=202) and the general population. To delve deeper into the gut microbiome's role, researchers are analyzing specific bacterial strains and their functions by reconstructing their genomes from metagenomic data.

The results revealed that individuals who developed colonic lesions after fecal sampling exhibited higher gut microbiome diversity compared to those who did not develop lesions. Moreover, the microbiome's composition and function differed among individuals with pre-existing or future lesions and varied based on the type of lesion. Notably, bacterial species from the Lachnospiraceae family and the genera Roseburia and Eubacterium were associated with future lesion development.

Ranko Gacesa, the study's lead author, highlighted the potential of some bacterial species in promoting colorectal lesions, citing the example of Bacteroides fragilis, which produces toxins that can lead to chronic low-grade gut inflammation. Colorectal cancer, a significant health concern in Europe, often arises from pre-cancerous lesions in the gut. Detecting and removing these lesions is an effective preventive strategy, but current non-invasive detection methods like the fecal immunochemical test result in numerous false positives, leading to unnecessary colonoscopies. Dr. Gacesa suggested that the gut microbiome could enhance current tests and advance early detection methods for pre-cancerous lesions and colorectal cancer.