Researchers from Georgia Medical College Cancer Center have noted that in immunotherapy involving T-cell driving immune response, the use of simultaneous antibiotics can wipe out effectiveness in 3 out of 5 cases (Oncotarget Magazine).
Antibiotics are known to have an almost instantaneous impact on gut bacteria and these are essential in provoking T-cell response and immune system strength. Damage to the microbiome cause drug resistance and infection, especially in the world of drugs targeting cancer.
“Any negative impact of antibiotics on cancer treatment appears to go back to the gut and to whether the microbiota is needed to help activate the T cells driving treatment response”, according to Dr. Gang Zhou, immunologist at the Georgia Cancer Center and the Department of Biochemistry and Molecular Biology at the Medical College of Georgia at Augusta University.
Chris Woollams, former Oxford University Biochemist and a founder of CANCERactive said, "I am really pleased by the conclusions of this study. They verify what we observe day in day out with patients. Infections are often the biggest complication of anti-cancer drug usage, with antibiotics usually prescribed to prevent them. But then white blood cell counts can fall so low that patients have no defense against other bacteria, and that can be lethal. So, many people with lymphoma, for example, having stem-cell transplants are given 6 drugs to kill off absolutely everything. The result is that they are totally vulnerable to picking up a bug that can make them very ill indeed. It’s ridiculous.
Now we are hearing that you need T-cell strength to make drugs and especially immunotherapy drugs work. What a surprise!! We’ve covered this in Cancer Watch before, but it is simply ignored in practice. Oncologists need to understand the different types of therapy they are giving and the importance of maintaining the gut microbiome strength in each”.
Chemo is increasingly packaged with newer immunotherapy drugs. Zhou and colleagues found clear evidence that antibiotics damaged the immune response and made drugs less effective.
However, it depends on the drug - for example, with drugs like CAR-T cell therapy, antibiotic use had no impact. But in one experiment, while mice with colorectal cancer which did not receive antibiotics were all cured after being treated with the chemotherapy CTX followed by CD4+T-cell therapy, that figure fell to just two in five, three weeks after treatment if antibiotics had been used.
Antibiotics also negatively impact CTX, when it’s used alone in lymphoma treatment.