Tiny organisms we carry in our bodies may help fight cancer

Probably the first thing that comes to our mind when someone mentions bacteria are those tiny creatures that cause many types of infections and diseases, but not all bacteria are that bad. The ones living in our bodies, so-called friendly bacteria, can actually be very useful when fighting some diseases.

A new study suggests that gut bacteria may help fight cancer. The same study also reveals that our friendly bacteria must be “strong and healthy” if we want the anti-cancer therapy to work properly, which means that antibiotics and cancer might not make a good team as it was previously believed.


Gut bacteria

The cyclophosphamide, a drug used to cure brain and blood cancers, was tested in the study. This drug works by encouraging the body to produce T-cells which attack cancer. The drug was given to mice that had sarcomas and skin cancer. The cyclophosphamide damaged the small intestine a bit, and a certain number of gut bacteria managed to “escape” and enter lymph nodes and spleen. After that it was the bacteria that encouraged the organism to produce T-cells, and not the drug (cyclophosphamide) itself. According to this the anti-cancer drug should only be used to affect the small intestine and the bacteria will take the main role in fighting the cancer.



In order to check the effectiveness of the anti-cancer therapy combined with antibiotics, another group of mice was tested. Researchers gave those mice an antibiotic along with the anti-cancer drug. The antibiotics had weakened gut bacteria and the whole cancer therapy was less effective than in the first group of mice.

The results show that the connection between bacteria and cancer needs more careful study. Although the results are promising it is still too early for patients to throw antibiotics out of their treatments.

“Extending the results to humans requires deliberate study as antibiotics can be life-saving in the setting of cancer and chemotherapy,” says Cynthia Sears, who researches gut bacteria at Johns Hopkins University in Baltimore. “One key source of life-threatening bloodstream infections in this setting can be the gut bacteria.”

Meanwhile, another study suggests that bacteria can play an important role in the activity of some anti-cancer therapies.

The team, at the National Cancer Institute in Frederick, Maryland, gave oxaliplatin to 50 mice and injected them various cancer cells. Oxaliplatin is a drug used in cancer treatment; more specifically it is used in human chemotherapy. This drug triggers the production of molecules that kill certain cells, including cancer cells.


Cancer cells

Half of the mice had first received antibiotics. After the period of three weeks 80% of mice had died. On the other hand 80% of mice that were antibiotic-free were still alive after the same period of time.

Even though this kind of treatment and connection between bacteria and cancer must be further examined, it looks like the human kind is a step closer to finding a cure for cancer. With the help of today’s technology and many new methods of treatment we should soon hold the cure in our hands.