H. pylori exposure linked to one in five bowel cancer cases

An exploratory meta-analysis involving nearly 49 million people suggests that exposure to the stomach bacterium Helicobacter pylori may be linked to approximately one in five bowel cancer cases globally. The study, published in Gastroenterology, found that individuals exposed to the bacterium faced a 1.6-fold higher risk of bowel cancer compared to those without exposure.

Researchers estimated that H. pylori could be responsible for roughly 22% of bowel cancer cases worldwide. However, this figure dropped to 12% when the analysis was restricted to 14 specific population-based and cohort studies. The highest potential links were identified in Mongolia (36%) and the Western Pacific region (25%), while China accounted for the largest total number of cases potentially linked to the bacterium.

The data suggests the association may be increasing in younger generations; the estimated proportion of cases linked to H. pylori rose from 9.5% among those born before 1947 to 15% for those born between 1963 and 1977. While some observational studies indicated that H. pylori eradication treatment was associated with a lower risk of bowel cancer, the reduction was only observed after a ten-year period. Researchers emphasized that these findings do not prove causation and noted that factors such as genetics, diet, and lifestyle also play significant roles.