How Chemotherapy Affects the Gut Microbiome

Food on a table next to a bottle of AtrantilCancer is an anxiety-inducing word for most of us. It’s a disease we fear more than most. Cancer can be a very fast-paced disease, but some of the issues that we associate with the disease itself might be the side effects of the treatments used to fight the tumors — chemotherapy. 

Chemotherapy is the most commonly used treatment for cancers. Even if you never had cancer or knew anyone close to you who had it, you probably have heard about it. 

What is interesting is that researchers are finding out that most of these symptoms are a result of the microbial changes within the gut from chemotherapy and not direct side effects themselves. 

What is chemotherapy?

Chemotherapy is a treatment that is used to stop and/or slow down cancer cell growth. The rapid abnormal cell growth is what makes cancerous tumors grow in the first place. So to stop this growth and spread, chemotherapy shuts that process down. 

Chemotherapy can be used as a stand-alone treatment or in conjunction with other treatments like surgery and radiation. It can help other (more aggressive) treatments to work better by slowing those cells down so the treatments have a chance to work.

There are several different types of chemotherapy that can be used. Doctors will decide which is best for the particular case of cancer that they are dealing with. Some of the factors that indicate which chemotherapy type will be the best and how often you’ll receive treatments include:

  • Stage of cancer (1-4)
  • Location of cancer
  • If cancer has metastasized (spread to other body parts)
  • Other health conditions and medications
  • The patient’s lifestyle and desires
  • Symptoms you’re having during chemotherapy treatment

Each individual case of cancer is as different as the person who is receiving treatment. So doctors will need to take into account each individual case before figuring out the best treatment plan. 

Side Effects from Chemotherapy

Chemotherapy is an aggressive treatment and it cannot determine the difference between cancerous and healthy tissues. This is where problems come into play. Everything that we put into our bodies has the ability to affect more than what we intend it to — chemotherapy is no different.

A few of the most common side effects that patients experience during chemotherapy include (this list doesn’t even really make a dent on the side effects most people experience):

  • “Chemobrain”
  • Nausea
  • Weakness
  • Fatigue
  • Appetite loss
  • Hair loss
  • Gastrointestinal problems (diarrhea/ constipation)

Chemotherapies aren’t able to penetrate the brain barrier so the chemobrain side effects (like cognitive impairment and behavioral changes) don’t really make much sense. It implies that these symptoms are an indirect effect of something else.

Most of these symptoms are related to dysbiosis. Doctors and researchers have noticed this correlation and started doing studies on if these are actually side effects from the chemo treatment itself or if it mainly affects the gut and they are side effects of severe dysbiosis.


Chemos Effects on the Gut

Most medications end up causing gastrointestinal issues in some form (constipation, bloating, diarrhea, gas, etc.). Chemotherapy treatments were found to accumulate in the intestines. This would explain why it’ll disrupt the normal flow of digestion. 

Think of an assembly line. Things are placed at different stations to take care of individual jobs. When a new shipment arrives it goes to its designated area and the flow continues. However, if a new, unknown, and unexpected shipment comes in, it disrupts the flow of everything else since it needs to be incorporated too. 

This is what is happening within the gut when there is an accumulation of medications like chemo. Our guts don’t actually know what to do with the substance, so it tries to deal with its normal jobs and figure out what to do with this new material that it has no knowledge of. The gut will either try to extract nutrients from the material (often resulting in constipation) or send it through the digestive system to get rid of it (causing diarrhea). 

Both of these options result in gastrointestinal (GI) inflammation and dysbiosis. When the GI tract becomes inflamed it allows for bacterial translocation which will affect all other body systems, microbiomes (oral and vaginal mostly), and cells. Inflammation will become systemic leading to all of the other symptoms we see experienced during chemotherapy treatments. 

The balance of bacteria found in another study shows that healthy bacterial strains were lowered after chemotherapy treatment. Meanwhile, unhealthy strains that lead to the degradation of the mucosal lining were increased. This direct change in the gut microbiome will significantly alter host health. 

Altering Gut Health to Improve Chemo Treatment and Side Effects

Cartoon of a woman experiencing the symptoms of going through chemotherapyCertain gut bacteria are able to break down different types of chemotherapies. Escherichia coli and Klebsiella pneumoniae have been found to easily break down doxorubicin (chemotherapy). During a study, when these bacteria were present they were able to “protect” the microbiome from the deleterious effects of doxorubicin. 

Oftentimes to replenish lost bacteria, doctors will suggest taking probiotics or eating probiotic-rich foods. In cancer patients, taking probiotics can actually be dangerous in some cases. 

The things that your gut microbes need to be able to create more of the healthier strains of bacteria (without exposing yourself to the potential dangers of probiotics) are prebiotics and postbiotics

Prebiotics are foods that your good bacteria will ferment and feed off of to create more healthy strains of bacteria to fill your microbiome with (fending off the unhealthy ones when they try to enter).

Postbiotics are the metabolites that are released after your bacteria enjoy their prebiotic meals. These metabolites like short-chain fatty acids, antioxidants, and other nutrients are then sent throughout your body to help heal itself. 

To get these special nutrients you’ll want to eat plant-based foods, like:

  • Fruits
  • Vegetables
  • Nuts
  • Seeds
  • Tea

All of these foods will help to nourish your microbiome and help good bacteria grow

Since poor appetite is a common side effect, you may find it hard to get enough of these foods in your diet to make a difference. Ask your doctor about taking Atrantil as a supplement that provides you with polyphenols, prebiotics, and probiotics

It was created to help nourish the microbiome and deal with GI issues like gas, bloating, and constipation. While it likely won’t avoid all of these symptoms for you (keep in mind chemotherapy is very aggressive) it may help to alleviate some of them. 

Cancer treatment is a difficult time and takes up a good portion of your life. By doing what you can (and listening to your body for when you need a break or a nice little walk in the fresh air) will help to make a difference in your mood and outcome. 

If you are dealing with the harsh side effects of chemotherapy, ask your doctor about the gut impact on your treatment. If someone you know is dealing with cancer and chemotherapy, share this article with them to see if it might help their situation to improve. One more good day is one less bad day and we’d love to see you have more good than bad.