Why Probiotics and Prebiotics Are So Crucial During Chemotherapy

Image Source: freedigitalphotos.net / cuteimage

Image Source: freedigitalphotos.net / cuteimage

Why Probiotics and Prebiotics Are So Crucial During Chemotherapy

Because there are so many of you undergoing chemotherapy right now, I thought it might be helpful to explain why probiotics and prebiotics are so crucial during chemotherapy (and afterward).

It’s All About The Good Bacteria

The normal healthy intestinal system contains about 100,000 billion bacteria and these bacteria are beneficial to our health. When beneficial bacteria are present, they help us to absorb and digest the food we eat, they keep out bad bacteria and carcinogens, promote healthy metabolism, reduce systemic inflammation, enhance immunity (it is said that 80% of our immune system resides in our guts!), and even support good mental health. Indeed, it is said that at the core of many health concerns there is an imbalance of intestinal bacteria.

Why Chemotherapy Causes A Problem With Good Bacteria

Chemotherapy causes a problem because these drugs go after any rapidly dividing cells, including the cells of the intestinal tract, which are renewed every 4-5 days. That’s why chemotherapy is so hard on digestion. From the mouth to the anus, these cells are killed off unselectively, along with the beneficial gut bacteria.

Supplementing With Probiotics Is Absolutely Crucial For 6 Big Reasons:

1. Probiotics help to replace some of the beneficial bacteria lost during chemotherapy and radiation.

2. Probiotics  help to clean out intestines of potentially toxic pathogens like candida, as well as chemicals and carcinogens (cancer-causing agents).

3. Probiotics appear to help chemotherapy work better. One study on mice revealed that when intestinal bacteria is compromised, chemotherapy drugs don’t work as well as they should [1]. Another study revealed that the commonly-used chemotherapy drug cyclophosphamide relies partially on its capacity to mobilize certain bacteria from the gut into the bloodstream and lymph nodes.  Once inside the lymph nodes, these bacteria stimulate the immune system, which then increases the body’s ability to fight a malignant tumor. [2]

4. Probiotics help to absorb minerals and even produce vitamins.

5. Probiotics help the immune system.  Most alternative health practitioners are aware that supplementing with probiotics provides good support for the immune system and science is getting on board too.  2014 research published in the Journal of Science and Medicine in Sport found that rugby players in New Zealand had about 40% fewer colds and gastrointestinal infections when taking probiotics, compared to taking a placebo [3]

6. Probiotics help to reduce inflammation in the gut [4],  indeed systemic inflammation is reduced when probiotics are taken regularly. Since cancer is an inflammatory process, anything that reduces inflammation is well worth including.

While it is true that some of the beneficial bacteria from your probiotics supplement may be obliterated by chemotherapy drugs, it is recommended to take them anyway in the hope that enough will survive to protect against unwanted organisms such as candida and Clostridium difficile, a particularly nasty form of bacteria that causes infectious diarrhea that can be severe enough to kill.

Other Helpful Things To Protect Gut Flora

Probiotics also come from certain foods.  Including these foods in your daily diet will also help the beneficial bacteria in the gut: sauerkraut, kimchi, kefir, kombucha, miso soup, natto, tempeh, pickles, spirulina.

You can also include prebiotics, which  is indigestible fiber that stimulates the growth of and provides the food for beneficial bacteria in the gut. Include things like asparagus, artichoke, leek, garlic, onion, beans, chickpeas, and lentils.

Inulin is one of the indigestible fibers that good gut bacteria lives on and one of the good things about inulin is that studies on rats indicate it also increases magnesium and calcium absorption  [5], important if you are prone to osteoporosis, as many of us are past a certain age.

Meditation is one surprising modality that actually assists gut flora by alleviating stress, which is a known factor for disrupting healthy gut bacteria.

Avoid antibiotic use whenever possible but if you do absolutely have to have a course of antibiotics, make sure to take probiotics and prebiotics because supplementing is known to reduce an overgrowth of bad bacteria while taking antibiotics. Be aware, however, that there are those who feel that our bodies never fully recover after antibiotic use. Dr Martin Blaser has a very interesting article in the Journal Nature about antibiotic use. He says “Early evidence from my lab and others hints that, sometimes, our friendly flora never fully recover” [5]. This is also mentioned in reference  [1] below.

Avoid eating loads of sugar and carbohydrates, even artificial sweeteners, which are known to harm beneficial bacteria.

If you are undergoing chemotherapy it is a good idea to keep an eye on the possibility of candida developing.  For more information on how to do that, see my article What Is The Candida Breast Cancer Connection.


1.  Gut microorganisms may determine cancer treatment outcome – http://medicalxpress.com/news/2013-11-gut-microorganisms-cancer-treatment-outcome.html

2.  The intestinal microbiota modulates the anticancer immune effects of cyclophosphamide – http://www.ncbi.nlm.nih.gov/pubmed/24264990

3.  Probiotic supplementation reduces the duration and incidence of infections but not severity in elite rugby union players – http://www.ncbi.nlm.nih.gov/pubmed/24045086

4. The Roles of Inflammation, Nutrient Availability and the Commensal Microbiota in Enteric Pathogen Infection – http://www.ncbi.nlm.nih.gov/pubmed/26185088

5.  Stimulatory effect of inulin on intestinal absorption of calcium and magnesium in rats is modulated by dietary calcium intakes – http://link.springer.com/article/10.1007%2Fs00394-004-0526-7

6. Stop The Killing of Beneficial Bacteria, by Dr Martin Blaser – http://www.ncbi.nlm.nih.gov/pubmed/21866137

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Why Chemo Causes Constipation

Image Source: MorgueFile / Flying Pete

Image Source: MorgueFile / Flying Pete

Why Chemo Causes Constipation

I get some very interesting questions sometimes as a breast cancer coach and today one of my clients asked a very good question: “Why does chemo cause constipation?”

Being the naturally inquisitive sort, I looked into this when I was going through chemotherapy, I wondered the same thing.  I could understand the digestive changes because chemotherapy drugs are targeting all of the rapidly growing and dividing cells, which is one of the reasons our mouths and digestive tracts and even hair suffer the effects of certain chemo drugs – they are lined with rapidly dividing, quick growing cells.

Certain Chemotherapy Drugs Cause Constipation Because…

For one thing, a certain class of chemotherapy drugs called vinca alkaloids affect the nerve supply to the gut.  Vinca alkaloids are a class of cell cycle-specific specific drugs that work by reducing the ability of cancer cells to divide.  These compounds include vinblastine, vincristine, vindesine and vinorelbine.  If you want to know more about how these drugs work, just look them up on Wikipedia, there is a lot of really interesting information about them there.

To complicate matters, some of the painkilling drugs (especially morphine based drugs) and anti-nausea meds that are prescribed just make the constipation problem worse.

Some Helpful Suggestions for Chemo Induced Constipation

  • Eat foods high in fiber like whole grains, vegetables and some fruits (see my compote recipe below);
  • Drink plenty of filtered water and freshly prepared juices each day (some doctors will rule against fresh fruit and vegetables for certain kinds of cancer treatments);
  • Exercise for 20-30 minutes – things like yoga, tai chi and walking are highly recommended;
  • See my article Natural Remedies for Chemo-Related Constipation for the recipe for one very effective herbal remedy you can either make yourself or have a naturopath mix up for you (scroll down the page for that recipe, it’s toward the bottom under Constipation Herbal).  See also the great recipe for Prune, Fig & Raisin Tea on that page.

Date, Apple, Prune & Apricot Compote Recipe

I used this recipe and found it absolutely delicious and very helpful for chemo induced constipation.  You need 2 organic apples, about 10 organic prunes (pitted), 3 organic dates, 5 organic apricots and about 1/2 cup filtered water.  Wash the apples and cut them into wedges, leaving the skin on (removing the seeds).  Place the wedges in a saucepan with water, prunes, dates and apricots.  Cover with a lid and place over medium heat.  Bring to a boil and simmer for around 3-4 minutes, remove the lid and stir the fruit up.  Cook the fruits just until soft and serve warm.  Sprinkle with freshly ground flaxseed or soaked chia seeds.

When to Seek Medical Help for Constipation

If you are constipated for more than 3 days, tell your doctor or nurse.  If you are having sharp abdominal pains, a fever, an inability to pass gas, nausea and vomiting (which admittedly can be caused by the chemotherapy drugs themselves but if it seems to be related to your constipation), or your stomach is distended and feels hard to the touch, get in to see your doctor right away.

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Tips And Support For Chemotherapy Digestive Problems

Photo courtesy of Ohmega 1982 and freedigitalphotos.net

Photo courtesy of Ohmega 1982 and freedigitalphotos.net


Your doctor may have explained that chemotherapy targets any fast moving cells, because cancer cells are busy dividing and replicating themselves at a very quick rate.  What your doctor may not share with you, however, is that your digestive tract has those same kinds of cells – the average cell lining your digestive tract changes over daily.  So chemotherapy targets them too and this can cause a whole host of associated complaints.  The damage, usually temporary, can make you pretty miserable, so here are my best tips and support for chemotherapy digestive problems.

The first thing you need to realize is that good intestinal health is the key to surviving chemotherapy.

Are You Experiencing Any Of These On Chemotherapy?

These problems are commonly experienced while on chemotherapy: mouth sores, taste changes, aversions to certain foods (even water!), diarrhea, constipation, incontinence, nausea and/or vomiting.  None of them are very nice to endure, so keep reading!

6 Tips For Chemotherapy Digestive Problems

1. Mouth sores – This usually occurs 7–14 days after chemotherapy infusions. Salt water rinses are extremely helpful.  Here’s some info on how to do them:

  • 1 teaspoon sea salt (please don’t use normal table salt, it is NO good for your health)
  • One cup of warm filtered water (warm water is more soothing and dissolves the salt quickly)
  • The water MUST NOT have chlorine in it, because that can further irritate your sore mouth, so do not use tap water unless your water comes from a well.  If you don’t have access to a filtration unit (even a Brita filter will be good enough to remove the chlorine) you can leave chlorinated water out in a wide mouth container, and in 24 hours the chlorine will have evaporated away, leaving chlorine-free water.
  • Rinse your mouth for about 30 seconds each time, and you can do this as often as you like during the day, but at least 3-4 times to be helpful.

2.  Taste Changes, Aversions To Certain Foods, Metallic Taste – Most chemotherapy drugs will cause you to lose your appetite to some degree and certain medications may cause changes to the way food normally tastes. Don’t worry, this doesn’t last forever.  Normal taste and smell usually returns two or three months after the end of treatment.  I remember I couldn’t stand the way red pepper tasted, oddly enough.  You may also have a constant metallic taste in your mouth.

Rather than eating the normal three meals per day, you might find it better to have several smaller meals when you feel hungry.  Liquid foods such as soups, fresh juices, and smoothies are often more palatable than solid foods.  Try using plastic utensils rather than metal as this sometimes helps to reduce the metallic taste.  It’s ultra important to keep up your nutrients, so concentrate on eating superfoods (contact me if you need a list).  If you find that strong odors bother you, try eating foods cold or at room temperature.

3.  Diarrhea – It is very important to replace the beneficial gut flora which is often destroyed by chemotherapy drugs.  Recent studies have indicated that taking probiotics during chemotherapy may actually protect and support intestinal stem cells which will help cancer patients survive toxic chemotherapy. 

Secondly, drink plenty of fluids and seek out foods that will help you retain or regain fluids, such as those low in fiber and high in salt, sodium, and potassium.  Avoid any alcohol, dairy products, and anything greasy, spicy, or high in fiber.  Please be aware that if you have diarrhea frequently over a long period of time, get to your doctor immediately.

4.  Constipation – I have already written a lengthy article about this: Natural Remedies For Chemo-Related Constipation.  Check it out, there are plenty of tips and advice in this article and a recipe for herbal medicine which I found extremely beneficial.

5. Incontinence –  Your doctor should be carefully monitoring your kidney and bladder function during your chemotherapy treatments.  You may experience frequent or uncontrollable urination, or an inability to urinate.   Getting the chemotherapy drugs out of your kidneys and bladder is the best defense against urinary side effects, so be sure to drink lots of filtered water and other clear liquids to flush out your system. Stay away from caffeine, it won’t help you right now.

6.  Nausea and/or Vomiting – You will be given anti-sickness injections or medications before your chemotherapy and tablets to take home with you.  You should take these regularly as prescribed, even if you are not feeling sick, as some anti-sickness drugs are better at preventing than stopping sickness once it has already begun.  I found it helpful to make a fresh ginger tea each morning.  Here’s how to do that:

  • Peel a knob of fresh, organic ginger, about 1″ in size, then slice it up and place that in the bottom of your cup
  • Pour boiling, filtered water over the ginger and let it steep for as long as you like, until it’s drinkable
  • You can also make a cold drink out of this by using a large glass refrigerator container, increase the amount of ginger you put in the jar, add boiling water, then let cool and refrigerate.  You could also add some slices of organic lemons as lemon and ginger are nice together and will give you some vitamin C too.

If you still experience nausea or vomiting, even after using your anti-sickness meds and the ginger tea, please tell your doctor as they may prescribe you a different anti-sickness drug that may be more effective. 

Two more helpful tips for nausea:  Eat a light meal prior to your chemotherapy infusion.  Concentrate on breathing slowly and deeply when feeling nauseated.  I would sit down and breathe with my eyes shut and soon found relief doing that.

Reference Articles:




I send my love to everyone taking this journey right now. If you would like my help with getting through breast cancer in an inspiring and ultra-healthy way, please sign up for my free e-newsletters on the right, or “like” me on Facebook (MarnieClark.com) and I’ll do my utmost to keep you informed and empowered on your healing journey… and beyond. 


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