Salmonella may increase risk of colon cancer, research shows

Infections with the salmonella bacteria can increase the risk of colon cancer, suspect researchers from Leiden University Medical Center (LUMC) and the University of Illinois Chicago. They found that people with colon cancer were more likely to have had mild salmonella infections.

The salmonella bacteria can cause abdominal complaints such as diarrhoea, nausea and vomiting. These complaints usually pass after a few days. Every year, 153 million people worldwide get such a mild infection with salmonella.

The link between more serious forms of salmonella, such as the variant that causes typhoid, and an increased risk of cancer had already been demonstrated, the researchers explained. But several mild infections, which people hardly notice, can also contribute to the development of cancer. Repeated mild infections makes it more likely that bacteria can enter and manipulate cells.

"We also found that several mild infections increased the growth rate of these intestinal tumors," said Jacque Neefjes, a professor of chemical immunology at Leiden University.

It is difficult to completely avoid salmonella infections because they are common in livestock and food, explained Professor Jun Sun from the University of Illinois Chicago. "However, exposure to the bacteria can be reduced by good hygiene practices when handling and preparing food."

The study was published in the scientific journal Cell Reports Medicine.