Chickens are often carriers of the Salmonella bacteria.© Photo ANP/SANDER KONING
Wilfred Simons
Leiden
Repeated food poisoning may play a role in the development of colon cancer. This is what researchers at the Leiden University Medical Center say on the basis of research into blood samples. Prevention is difficult.
Food poisoning occurs when food is contaminated with a so-called non-typhoid Salmonella bacteria. Such poisoning causes diarrhea and vomiting and, in addition to being very unpleasant, is sometimes even fatal. Every year, doctors worldwide count 153 million infections, of which 57,000 are fatal. There is also a Salmonella variant called typhoid fever, which is much more deadly. Typhoid fever is almost non-existent in the Netherlands because of our clean drinking water.
Postdoctoral researcher Virginie Stévenin of the LUMC laboratory of Neefjes says that a mild bacterial infection can give cells in the intestines a boost, causing them to ‘develop in the direction of cancer cells’. A subsequent infection can push the cell over the edge.
Antibodies
The Leiden researchers had access to a hundred human blood samples, in which they searched for antibodies against Salmonella. They found that patients who had developed colon cancer were also more likely to have been exposed to mild Salmonella infections. LUMC professor Sjaak Neefjes also found that the tumors grew faster after several mild infections. “Moreover, in a cell culture model, Salmonella appeared to infect the cells faster, with the potential to become fully transformed cancer cells.”
Professor Jun Sun of the University of Illinois, also involved in this research, believes that Salmonella does indeed influence cancer formation in a ‘multi-step process’. Proper heating of food and hygiene in the kitchen can prevent a lot of misery, but it remains difficult to avoid exposure completely. “Salmonella is common in livestock and food,” says Jun Sun. Meat, raw eggs and sprouts are especially notorious.