Gut Microbiome Variations and Colorectal Cancer Risk
Recent findings presented at United European Gastroenterology Week demonstrated that patients with precancerous colorectal tumours showed significant variations in their gut microbiome. The connection between the gut microbiome – the totality of microorganisms such as bacteria, fungi, and viruses that colonize the intestines – and precancerous tumours has been underexplored, the researchers indicate. While the fecal immunochemical test (FIT) is an existing non-invasive detection method used in the screening of colorectal cancer, it can produce a high number of false-positives. The study was conducted to shed light on the potential role of the gut microbiome in predicting the future onset on colorectal cancer.
The large-scale prospective study involved 8,208 participants, linking data from the Dutch Microbiome Project with the Dutch nationwide pathology database to identify all the recorded cases of colon tissue biopsies from the last 50 years. Researchers examined the gut microbiomes of 214 patients who had developed precancerous colorectal tumours prior to completing a fecal immunochemical test (FIT) between 2000 and 2015, and 305 patients who developed precancerous tumours following FIT testing between 2015 and 2022. Data from both patient groups were compared to data from patients who had normal colonoscopy results and the general population. The researchers also analyzed specific bacterial strains and their role within the gut.
Patients who developed precancerous tumours following a FIT showed a greater diversity in their gut microbiome compared to those who did not develop tumours. Bacterial species in the family of Lachnospiraceae and the genera Roseburia and Eubacterium were all linked with the future development of precancerous tumours. These findings suggest that a better understanding of the microbiome could lead to the improvement of existing screening tests and the advancement of early detection methods for precancerous colorectal tumours.