I am clearly a fan of a healthy bacterial flora in the gut. I have gone on record time and time again about how wanton destruction of the normal flora with antibiotics is one of the worst things you can do for your immune system. But I never considered just how far that extends until now.
There is no longer any doubt that the bacteria in your gut play almost THE pivotal role in what your immune system is doing. The delicate balance between the 400+ species of organisms in your gut and your immune system’s response to these organisms Is of critical importance. This is why autoimmune disorders and allergies may all stem from imbalances in the bacteria in the gut.
From birth, your immune system began to take a look at the organisms that were exposed to your immune system. This interaction happens in multiple places: the sinus membranes, the gums, the back of your throat (pharynx), your stomach and (obviously in women…) the vaginal vault. But nowhere is this interaction as strong as it is in the gut.
If the right blend of bacteria is present along the lining of the gut in infancy, the immune system develops a tolerance for these bacteria. This is a good thing. On the dark side, if the right blend of bacteria is not there, this tolerance never develops, and later in life the immune system learns to attack the bacteria in the gut, leading to tissue destruction and immune imbalances.
Prior to this blog post, I thought that it ended here. Boy was I wrong.
In this issue of Science, two articles turn this limited belief upside down. While the two are mice studies, the implications are likely very relevant to us humans as well. Both are related to the effects of chemotherapy, but I’ll cover each briefly.
In the first study, researchers looked at the effect that commensal bacterial (the bacteria that are supposed to be there and provide a mutually beneficial relationship) had on tumor response to CpG-oligonucleotide immunotherapy and platinum chemotherapy.
When antibiotics were used to destroy the commensal flora, or in mice that were raised in a completely germ-free environment, the mice’s own immune cells (tumor-infiltrating myeloid-derived cells) responded poorly to therapy. This resulted in lowered production of cancer-fighting immune messengers (cytokines like tumor necrosis factor). Even worse, one of the goals of platinum based chemotherapy, to create high levels of oxidative stress within the tumor cells to destroy them, was reduced in this group of bacteria-free mice.
In the second study, researchers looked at the interactions of cyclophosphamide (one of several important cancer drugs that works largely by stimulating the antitumor immune response of the body) with the commensal bacteria in the gut.
First, it was determined that cyclophosphamide had an effect on the bacteria in the gut, allowing for the movement of Gram-positive gut bacteria into the circulation, allowing them to reach secondary lymphoid organs like the spleen and lymph nodes. Once there, these bacteria create an immune response, leading to the production of immune cells that fight the tumor (T helper 17 and memory TH1 cells).
When researchers destroyed the bacteria or, once again used mice raised in a sterile environment, there was a reduction in the immune response and the chemotherapy did not work.
I cannot even begin to grasp the implications of what this means for cancer treatment. Sadly, many patients undergoing chemotherapy are steered away from probiotic supplementation for fear of the bacteria creating an infection that could run out of control. Based on this research, this fear may be shutting down cancer treatment success.
The first research article on probiotics came out in 1908, 106 years ago as of the writing of this article. STILL, after all this time mainstream medicine does not understand the power of probiotics on human health and disease even in its most basic constructs. Understanding and actively using the role of the bacterial flora in the gut in cancer treatment will likely not happen in our lifetimes with any degree of regularity.
Truly, truly sad for the cancer patient.