Addressing and Healing Gastrointestinal Issues Caused by Mold Toxins

By Dr. Susan Tanner, MD

When discussing the impact of mold on the body and its multiple systems, it is easy to miss the negative influence it can have on the gastrointestinal tract (GI tract). Many times patients mistakenly think that only foods or substances that are ingested can impact the gastrointestinal tract and digestion, but that is not the case. In fact, gastrointestinal symptoms from mold exposure can be multiple and far reaching, and must be recognized and addressed for a patient to recover. Much like the air that you breathe, if the GI tract is not as free of toxins as possible, it cannot maintain proper function.

How Your “Gut” Protects Your Health

When we refer to the “gut”, what we are talking about is the inner lining of the small intestine. This is a massively complex organ, much more than a simple conduit for food as it is digested. The lining of the gut is responsible for making immune cells, particularly Immunoglobulin A (IgA), and this is considered to be the body’s first line of immune defense. The lining is also responsible for absorption of our nutrition, including vitamins, minerals, amino acids from proteins, and fats.   Additionally, the buildup and break down of our brain chemicals, referred to as neurotransmitters, occurs in the gut. This is the reason that some medical practitioners refer to the gut as the “second brain”. So, you can see why, when someone is experiencing poor GI health, their cognition and moods are also impacted. In other words, when the second brain isn’t working right,  the first brain can’t either!

When the body is bombarded by toxins, this includes mycotoxins produced by mold, disruption to any or all of the gut’s functions can occur. Furthermore, the immune lining of the gut can be dramatically altered by chronically elevated levels of cortisol produced by the adrenal glands when the body is under stress, toxic, physical, and/or psychological, and a vicious cycle can emerge. The cycle looks something like this: The gut lining is altered by chronic stress, and becomes poorly protective. As a result, it can also become highly reactive (food allergies) to previously well-tolerated foods. Without protection and with the added inflammation, the gut is then more susceptible to the overgrowth of undesirable bacteria and yeast, and then becomes further compromised. Then, the cycle continues unless the proper interventions are taken, like reducing stress and getting to a safe environment.

Mold and Your Gastrointestinal System

When exposed to mold in the air, the mycotoxins from these molds circulate in the bloodstream, and may also be released into the bile from the liver as it does its job and attempts to clear toxins from the blood. When bile is released, the cells in the gut are exposed to the effects of the toxins. A healthy gut can weather this exposure, because it has an array of billions of beneficial bacteria, which actually help to increase the levels of IgA to support the immune system. But, in a compromised gut, toxins have dramatically reduced the number of these good bacteria and allow proliferation of undesirable and opportunistic bacteria and most notably, candida yeast.

Now, we all have a little bit of candida, and when it is in proper proportion to the rest of the organisms of the GI tract, it is protective against some forms of toxic bacteria which can cause severe illness. Unfortunately, though, when a body has met its “toxic load”, yeast can grow out of control. If yeast is allowed to become a predominant organism in the GI tract, it is extremely disruptive to the system with far-reaching symptoms. Additionally, candida produces its own mycotoxins, which cause symptoms quite a bit like those of the toxic molds in the environment.

Gastrointestinal Symptoms Caused by Mold

What can be obvious are the actual gastrointestinal symptoms that may present when things are out of balance. These can include chronic bloating, abdominal swelling, alteration in bowel habits, heartburn, indigestion, and stomach pain. What is less obvious is the connection with these gut-related issues to other symptoms.  For example, the development of food sensitivities is very common. Foods previously well-tolerated often become the cause of anything from skin rashes to headaches, brain fog and even depression. Making it even harder to pinpoint the link between the foods and the reactions is the fact that these food sensitivities may have up to a 24-hour delay between when a food is consumed and when symptoms are displayed. Sometimes it takes patients months to even realize that a food is what is causing their symptoms.

Addressing Gut Issues

In all mold-exposed patients, we try to address the gut to decrease problematic symptoms proactively, but also to protect the immune system from further damage. There are several steps to this process, but they must all be adhered to in order to be successful. Opportunistic bacteria and yeast are difficult to displace and can come right back if mold exposure continues and if the proper steps are not taken to care for this most important organ.

1. Diet:

  • Don’t put things in the system that feed the problem. Sugar and refined carbohydrates are absolute no-nos. We generally take away both gluten and dairy proteins initially as these are very large molecules, difficult to break down, and can cause more inflammation in the gut lining. In general, this avoidance needs to be followed indefinitely. Many patients remark that they feel so much better doing this that they have no desire to return to sugar, gluten or dairy.


  • Stay organic with your food sources as much as possible so as not to introduce other chemicals (pesticides, herbicides, growth hormones) into the system which add to the burden, lowering immunity.


  • Drink purified water. Chlorine in our water system kills bacteria but not yeast, allowing it to proliferate. A Zero Water filter pitcher is a helpful tool for accomplishing this.


  • Try not to eat the same things every day. Varying your food choices allows the system to not form antibodies to particular foods, thus decreasing your susceptability to food sensitivities.   There are blood tests available that may give you an idea of which foods are particularly problematic. Usually, once the GI problems are addressed, these foods may be able to be put back into the diet.

For more information and help on nutrition and diets for this, please go to and look at simple nutrition evaluation by Tammy Jett-Parmer, PA-C.

2. Cleanse:

  • Gently killing off the yeast and/or bacteria through prescription antifungal medications such as Nystatin or Diflucan may be necessary. Herbal and natural remedies such as CitriDrops Dietary Supplement, 5-8 drops in 4 ounces of water twice daily, are a gentler method and may be continued for as long as needed. Candida Rid is also a great natural option in capsule form. Beware, though, if you try to kill off yeast without conforming to the dietary controls, you run the huge risk of creating resistant forms of yeast that are very hard to control.

3. Repopulate & Replenish:

  • Replace the pathogenic bacteria and yeast with the beneficial ones.   Flooding the system with good bacteria helps to reestablish homeostasis. Probiotics, usually those that measure in the 10s of billions of colonies are necessary. Some excellent ones that are not overly pricey include Orthomolecular Orthobiotic Plus and Klaire Labs Therabiotic Plus or Pro5. These may be found on the Wellevate portal through website.


  • Digestive enzymes may also be very helpful, as when under stress, the body tends to shut down the production of enzymes leading to problems with indigestion and reflux. Enzymes taken with meals can help these symptoms dramatically.   Klaire Labs Vitalzymes Complete are a great option, and are also available in a chewable form.


  • Adding fiber to the diet through vegetables and low glycemic fruits gives the good bacteria a substrate to feed upon, raising levels of immunity. There are also some helpful immune boosters for the GI tract, such as Colostrum, that help to make the intestinal lining healthier and more resilient to the abnormal growth of candida.


  • Always keep in mind, however, that you MUST address the air you breathe in order to really get well. This means monitoring your home, car and work environments to be sure you are not being exposed to mold toxins. EC3 Mold Screening Test Plates and Diagnostic Test Plates are inexpensive tools for doing this and for staying on top of mold triggers in your environment.

When you follow these protocols you will not only experience less gastrointestinal symptoms, but also a clearer mind, less anxiety or depression, resolution of headaches, and better stamina overall. Remember a healthy gut means better nutrient absorption, lowered inflammation, and a healthier immune system.

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