In recent years doctors have blamed the prevalence of asthma and allergies on our lack of exposure to bacteria and on parents keeping their houses super clean. Due to lack of contact with germs, they say, our immune systems aren’t being given the chance to practice and we are becoming weaker as a result.
Now, doctors from University of Minnesota Masonic Cancer Center said that the bacteria salmonella may be useful in fighting cancer. By putting the bacteria into the patient’s body, where the tumor is, they hope it will then destroy the tumor.
The medical profession has known since the 19th century that exposure to infection sometimes cures cancer patients and because of their observations of this, in the 1860’s they decided to do an experiment by putting a patient with a large tumor in the same room as another patient with a serious infection. The tumor became infected and began to shrink rapidly and almost disappeared. Unfortunately the experiment failed because as well as killing the tumor, the infection also killed the patient whose immune system was weakened due to the cancer.
"Many bacteria and viruses - even harmful ones - can be used to fight disease," said Edward Greeno, M.D., lead researcher on the new clinical study and Medical Director of the Masonic Cancer Clinic. "We believe it may even be possible to use bacteria to fight cancer."
He added that to do this they had to to devise a way to introduce the salmonella to the patient without actually making them sick.
The team decided that the way to do this was to turn the salmonella into a weapon by genetically modifying it. They weakened it so that theoretically it wouldn’t cause infection--although other weakened bacteria in medicines have been known to mutate--and then adding Interlueken 2 (IL-2).
Greeno's Medical School colleague, Dan Saltzman, M.D, said, "You could think of IL-2 as a guard dog that sniffs around looking for threats inside the body." When it finds one, it calls in an attack by the immune system it to make it actively detect the tumor.
Salmonella naturally likes to grow inside cancer cells so this seemed the ideal type of bacteria to use to kill cancer.
"This probably won't replace other ways of treating cancer such as chemotherapy and radiation," Greeno said. "But it's a promising area of study and we hope it can be a potent tool in our battle against cancer. It also has potential to be a much cheaper and less toxic alternative to chemotherapy and radiation."
Patients are currently trialling the idea by swallowing the GM salmonella mixed with water. No one knows yet of the safety of the treatment or the long-term implications of using a genetically altered bacteria, but the medical team are hopeful.
Sources: University of Minnesota Press Release, 9th March 2011.
Rapid Serogroup Switching in Neisseria meningitidis , N Engl J Med 2000; 342:219-220 - http://www.nejm.org/doi/full/10.1056/NEJM200001203420319
Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/. She is author of the book, 'Breast Milk: A Natural Immunisation,' and co-author of an educational resource on disabled parenting, in addition to running a charity for people damaged by vaccines or medical mistakes.