One in five cases of bowel cancer worldwide may be linked to a common stomach bug, research suggests. An international study using data from 48 million people found that exposure to H. pylori bacteria was linked to a 1.59-fold increased risk of the disease.
Most infections do not cause symptoms but some people will experience ulcers or inflammation of the stomach lining. Up to 40% of people in the UK are thought to have H. Pylori in their stomach. It is spread through contact with an infected person’s vomit, stool or saliva.
H. pylori is a known cause of stomach cancer but the relationship between H. pylori and bowel cancer remains “highly controversial”, according to experts who set out to explore the potential link.
The team, led by researchers from the University of Hong Kong and the University of California San Diego, analysed data from 43 previous studies.
They wrote in the journal eGastroenterology: “H. pylori exposure may be related to an estimated 22% of global CRC (colorectal cancer) cases under a causal assumption.”
Four studies included in the analysis looked at H. pylori “eradication” with antibiotics and continued cancer risk.
These suggested that clearing the infection could reduce bowel cancer risk, but only after 10 years.
The findings also suggested the proportion of bowel cancers linked to H. pylori exposure rose in more recent decades (1960s and 1970s).
The researchers noted that many other factors play a role in bowel cancer risk, including genetics, age, lifestyle and diet.
When H. Pylori causes gastritis, symptoms include belly pain, feeling sick, belly bloating and burping.
It is typically treated with a combination of medication to reduce the amount of acid in the stomach and antibiotics.
This story originally appeared on Express.co.uk
