The Study
Geographic and age variations in mutational processes in colorectal cancer
This study looked at the DNA mistakes in cancer cells from people in 11 countries and found that certain mistakes were more common in places with more cancer and in younger patients. But it didn't watch people over time to see if the bacteria came first — so we can't say the bacteria caused the cancer, only that they're often found together.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists found that a toxin made by certain gut bacteria leaves a unique fingerprint in the DNA of colon tumors — and this fingerprint is much more common in young people with colon cancer.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this suggests that exposure to these bacteria early in life may be a major reason why colon cancer is rising in young adults.
- 2The bacterial toxin signature was 3.3 times more common in people diagnosed before age 40 than after 70, and caused about 1 in 4 of the key DNA errors that start colon tumors.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nature
Year
2025
Authors
M. Díaz-Gay, Wellington Dos Santos, Sarah J. Moody, Mariya Kazachkova, Ammal Abbasi, Christopher D. Steele, R. Vangara, S. Senkin, Jingwei Wang, Stephen Fitzgerald, E. Bergstrom, Azhar Khandekar, Burçak Otlu, B. Abedi-Ardekani, A. D. de Carvalho, Thomas Cattiaux, Ricardo Cortez Cardoso Penha, V. Gaborieau, Priscilia Chopard, Christine Carreira, S. Cheema, Calli Latimer, Jon W. Teague, A. Mukeriya, D. Zaridze, Riley Cox, Monique Albert, Larry Phouthavongsy, Steven Gallinger, R. Malekzadeh, Ahmadreza Niavarani, Marko Miladinov, Katarina Erić, Sasa Milosavljevic, S. Sangrajrang, M. Curado, S. Aguiar, R.M. Reis, M. T. Reis, L. Romagnolo, D. P. Guimarães, I. Holcatova, Jaroslav Kalvach, C. A. Vaccaro, T. Piñero, B. Świątkowska, J. Lissowska, Katarzyna Roszkowska-Purska, Antonio Huertas-Salgado, Tatsuhiro Shibata, Satoshi Shiba, S. Sangkhathat, T. Chitapanarux, G. Roshandel, Patrícia Ashton-Prolla, Daniel C Damin, F. H. de Oliveira, Laura Humphreys, T. Lawley, Sandra Perdomo, Michael R. Stratton, Paul Brennan, Ludmil B. Alexandrov
Related Content
Claims (8)
Colorectal cancers diagnosed before age 40 are more likely to show specific DNA damage patterns linked to colibactin-producing bacteria than cancers diagnosed after age 70, suggesting that exposure to these bacteria earlier in life may be associated with faster development of tumors in the lower colon and rectum.
In colorectal cancers infected with bacteria that produce colibactin, a specific pattern of DNA damage caused by this toxin accounts for about one-quarter of harmful mutations in the APC gene, which is known to initiate tumor development.
In 11 countries, regions with higher rates of specific DNA damage patterns linked to colibactin-producing bacteria also have higher rates of colorectal cancer, suggesting that differences in exposure to these bacteria may help explain why cancer rates vary by location.
DNA damage caused by the bacterial toxin colibactin is found in the earliest genetic changes in colorectal cancer, suggesting that exposure to this toxin happens early in life and helps create the initial mutations that lead to cancer.
Colorectal tumors with specific DNA damage patterns caused by colibactin often do not contain the bacteria that produce it at the time of diagnosis, suggesting the bacteria were present earlier and have since been cleared.
DNA damage from certain bacteria in early childhood may lead to colorectal cancer that appears later in adulthood.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.