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Could Your Gut Bacteria Help Your Immune System Fight Cancer?


A recent study done at the University of Chicago found that mice that received the live bacteria species Bifidobacterium had a marked increase in anti-tumor T cell responses – 2


The researchers fed live gut bacteria Bifidobacterium to mice along with injections of anti-PD-L1 antibody.

Now let’s backtrack a little. Decades ago some experiments hinted at harnessing the immune system to fight cancer. When a normal cell starts displaying abnormal proteins on their membranes it gives a signal to the immune system to attack them and it generally works. But for some reason some cancer cells evade this attack and by the time these cancer cells are detectable the balance of power between the immune system and the cancer cells has shifted in favor of the growing tumor and a state of immune intolerance has been established. Understanding this mechanism is what prompted the research forward and since then it has been promising.

Injections of anti-PD-L1 are one of many drugs that have proven very promising in killing tumors by harnessing the power of the immune system.

In this recent study the combination of live gut bacteria along with the injection is new. The researchers were actually surprised by the results, and it could have implications for the results you could see from probiotics supplements.

“Our results clearly demonstrate a significant, although unexpected, role for specific gut bacteria in enhancing the immune system’s response to melanoma and possibly many other tumor types,” said study director Thomas Gajewski, professor of medicine and pathology. 1

These new drugs have had a dramatic impact on treatment of several tumor types, including melanoma, lung cancer, head and neck cancers and others. But only a minority of patients—one-third or less—have a vigorous response. Cancer researchers have wondered why so few benefit. 1

The answer came to them from the mice they were using in experiments. Some seem to have a stronger immune response and they found the answer in the gut bacteria of the stronger mice: the Bifidobacterium!

Ultimately they found that introducing this bacteria was just as effective as treating them with anti-PD-L1 antibodies, resulting in significantly slower tumor growth.

But combining the benefits associated with the bacteria with anti-PD-L1 treatment dramatically improved tumor control.

The researchers are busy investigating the effects of the other gut bacteria against cancer and other diseases.


In the meantime keep eating bacteria rich yogurt, kefir and fermented foods.

Avoid sweets and if you have to take antibiotics make sure to replenish your gut bacteria with Bifido and Lactobacillus.