Study Links H. pylori Exposure to One in Five Bowel Cancer Cases - Video

Exposure to the stomach bacterium Helicobacter pylori may be linked to around one in five bowel cancer cases worldwide, according to an exploratory study published in eGastroenterology.

Researchers analysed data from 43 studies involving nearly 48.7 million people to examine whether H. pylori infection could contribute to the global burden of bowel cancer. They found that people exposed to the bacterium had about a 1.6-fold higher risk of bowel cancer than those without exposure.

Using global cancer data from 2022, the researchers estimated that around 22% of bowel cancer cases could potentially be attributed to H. pylori exposure. However, the estimated proportion fell to 12% when the analysis was limited to 14 population-based and cohort studies, suggesting that the overall figure should be interpreted cautiously.

The highest estimated proportions were seen in the Western Pacific region and Mongolia, at about 25% and 36%, respectively. China had the largest estimated number of bowel cancer cases potentially linked to H. pylori, at around 139,619.

The analysis also suggested that the association may have become stronger among people born in more recent decades. The estimated proportion rose from 9.5% among people born before 1947 to about 15% among those born between 1963 and 1977.

Interestingly, four observational studies found that H. pylori eradication treatment was associated with a lower bowel cancer risk, but the reduction was observed only after 10 years.

Researchers stressed that the findings do not prove that H. pylori causes bowel cancer. Many other factors, including genetics, age, diet and lifestyle, also influence cancer risk.

They said large, long-term studies and randomised clinical trials are needed to determine whether treating H. pylori can actually prevent bowel cancer. Any widespread eradication strategy would also need to consider antibiotic resistance, treatment side effects and local healthcare capacity.

REFERENCE: Li, Y., et al. (2026). Global and regional burden of colorectal cancer potentially related to Helicobacter pylori exposure: a risk attribution modelling study. eGastroenterology. DOI: 10.1136/egastro-2026-100436.