Dr. Paul Deglmann
Meghan Feir Walker
Many people don’t realize how much the gut can be impacted by mold and mycotoxins, but it’s a common result of ongoing exposure. When you’re experiencing chronic gut symptoms, leaky gut, and/or SIBO, mold and mycotoxin exposure could actually be a driving factor in your ongoing digestive distress and dysbiosis. Let’s dive into how mold and mycotoxins in the environment impact gut health and go over what you can do to combat their effects.

What is mold exposure, and how do mycotoxins enter the gut?
Mold and mycotoxin exposure can come from a wide range of sources. It’s inevitable you will run into some level of exposure from both outdoor and indoor environments—even in food. However, certain types and levels can be extremely detrimental to your health, especially from ongoing exposure.
The main mold and mycotoxin exposure that causes ongoing problems for people is from spending consistent time near or in water-damaged building materials in the home, workplace, cabin, or vehicles.
Common areas of mold and mycotoxin exposure:
- House
- Cabin
- Any building you spend a lot of time in
- Work
- School
- Church
- Vehicle
- Camper/RV
- Any other water-damaged building
Main sources of water-damaged materials:
- Sheetrock
- Lumber
- Insulation
- Wallpaper
- Plaster
- Carpet/carpet padding
- Dust
When you see visible mold, you are seeing a collection of mold spores. Mycotoxins are invisible and odorless toxins released by mold spores like a gas. While you can absolutely have an allergy to the mold spores themselves (and many people do), the mycotoxins are typically what make people the most sick.
When we breathe, mycotoxins can enter the body, but they can even enter through our skin due to their small size. When you consider the average person takes 20,000 breaths per day, exposure can be significant when mold and mycotoxins are present in your environment.
And what about food? Can moldy food give a person mold illness?
While every food can get moldy, certain foods are extra prone to harboring mold and mycotoxins. However, even these mold-prone foods usually aren’t the main problem mold-exposed individuals face because the levels are low enough and don’t typically cause chronic harm. The levels in foods are nowhere near the cumulative amount of mycotoxins you breathe in from water-damaged materials.
However, if you’re already highly sensitive and have had significant exposure from living, working, or driving in contaminated buildings or vehicles, you can become hypersensitive to mold and mycotoxins in foods.
Foods high in mycotoxins:
- Grains
- Cereals
- Nuts
- Peanuts
- Coffee
- Beans
- Dried fruits
- Animal products from contaminated feed
- Alcoholic beverages

How mycotoxins impact the immune system/inflammation
Mycotoxins can significantly increase inflammation and are also well known for suppressing the immune system and disrupting immune tolerance. This can lead to multiple food, chemical, and environmental sensitivities and allergies.
How mycotoxins affect the gut barrier and microbiome
Mycotoxins are well known for disrupting tight junctions, damaging the gut barrier, and causing leaky gut. This allows the passage of undigested food proteins, toxins, and LPS (an endotoxin from gut bacteria) to enter the bloodstream and increase inflammation.
When mycotoxins enter the gut, they can kill off or suppress many of our beneficial/keystone bacteria, like Lactobacillus and Bifidobacterium. This can allow opportunistic/dysbiotic bacteria to survive more easily. Some of these opportunistic/dysbiotic bacteria include types such as Klebsiella, Pseudomonas, Morganella, Citrobacter, Enterobacter, Prevotella, and many others. Mycotoxin exposure can also allow yeast/fungi, such as Candida, and parasites, to survive more easily.
Mycotoxins can also deplete essential nutrients for immune health, detoxification, and many other functions of the body, such as glutathione (the master antioxidant), zinc, and magnesium, which are needed nutrients for the beneficial bacteria to thrive.
Common digestive symptoms linked to mold in the gut
Mold and mycotoxins can cause a vast array of symptoms, from neurological issues to many immune problems like allergies. However, these are the most common digestive symptoms linked to mold and mycotoxins in the gut.
Common digestive symptoms from mold and mycotoxins:
- Gas/bloating
- Abdominal pain or cramping
- Diarrhea
- Constipation
- Acid reflux or heartburn
- Nausea or loss of appetite
- Food sensitivities or reactions to food
Please note: The severity of symptoms can differ based on the amount of exposure and length of exposure, along with other things like genetic predispositions, how healthy the diet is, how many other toxins someone is exposed to, the health of the microbiome prior to the mold exposure, how many nutritional deficiencies are present, how healthy the adrenal glands are, etc.
To learn more about additional symptoms that can be caused by mold and mycotoxin exposure, click here.

Mechanisms behind symptom development
Mold and mycotoxins can cause significant inflammation and oxidative stress. The impact on the gut and microbiome can negatively impact nutrient absorption, which then increases the chances of developing nutritional deficiencies.
Mold exposure and increased levels of mycotoxins can also make certain people more susceptible to SIBO. This can occur because the mycotoxins can damage the gut lining/barrier, making leaky gut more likely to occur. It can also decrease the activity of the MMC, which slows the movement of stool and microbes (like bacteria and toxins) down the GI tract.
Mycotoxins can also greatly suppress the immune system, which can allow bacteria to become overgrown. This, combined with a decrease in MMC activity, can allow the bacteria to travel from the colon up into the small intestine, often resulting in SIBO.
Strategies to protect and support gut health
In order to know how to help your situation, it’s important that you recognize your sources of exposure. After that, to protect and support optimal gut health, you need to make sure you’re breathing in clean air. Whether you’re in your home, cabin, workplace, or vehicle, you need to make sure that the air you’re breathing is filtered and not exposing you to more mold and mycotoxins.
To make sure you’re not getting continual mold and mycotoxin exposure, here are some tips to prevent and improve your situation.
Strategies you can take to reduce mold and mycotoxin growth and exposure:
- Keep indoor humidity at less than 45% (in the hot/humid months, dehumidifiers and AC are typically needed to keep the levels low)
- Filter the air with a good air filter/air purifier
- Get the home and air tested by a reputable mold inspector, especially if there is a history of water damage or if mycotoxin levels are high in the body
We also encourage our patients to eat gut-healthy foods every day. This can beef up your digestive strength and microbial diversity.
Foods that support detoxification and minimize mold and mycotoxin effects:
- Daily veggies rich in color
- Bitter greens
- Cruciferous veggies
- Healthy fats like olive oil, avocado oil, coconut oil, and tallow
- Natural fibers that act as binders: chia seeds, flaxseed, psyllium husk, etc.
Please note: There are some people who may not be able to tolerate some of these foods due to an increase in their GI symptoms. Please work with a practitioner who considers your health history and symptoms before trying a new diet.
When the body is in a healing environment where clean water, fresh air, and healthy food are available, our bodies’ immune systems can properly help us heal, repair, and recover.
Whether you’re recovering from mold illness and/or other conditions, or you just want to lead a healthy lifestyle, these basic tips can help you set up a clean, healthy environment for yourself and your family.
Dr. Paul’s basics for healthy living:
- Drink clean water
- Eat healthy food
- Get daily sunshine
- Move our bodies/exercise
- Manage our stress load
- Get adequate sleep
- Breathe clean air
There are many steps beyond these basic concepts, but this is where working with an experienced functional medicine practitioner may be needed to provide more personalized support.
When to explore further—testing and functional evaluation
When we have reasons to believe mold and mycotoxins may be a driving force in a patient’s symptoms, in addition to testing the home, workplace, cabin, RV/camper, or vehicle for mold, at RHS, we always test a patient’s mycotoxin levels. We either test for the presence and number of mycotoxins in the urine or the immune response to mycotoxins in a blood test.
In addition to mycotoxin testing, we also consider these other tests:
- Stool testing
- Organic Acid Testing (OAT)
- Full environmental toxins panel
- Nutritional deficiencies panel
- Food sensitivity/food allergy testing
- Adrenal/cortisol panel
- Comprehensive hormone panel
- And others
Take charge of your gut health today
Working with a functional medicine practitioner may be the missing link in your healing journey, especially when dealing with mold and mycotoxin illness. Mold and mycotoxins can cause your gut barrier to break down, causing various symptoms and immune dysfunction.
Along with taking the necessary precautions in your home and other environments to cut down on the chances of developing mold in the first place, getting professional help and testing for your health and home may be the key to getting better.
You need to understand the root cause(s) of your gut and inflammation problems, and you need a one-size-fits-one approach to heal. Using a general protocol for everyone won’t solve the problem for many patients because everybody has unique issues they’re experiencing.
Thorough, accurate, and honed-in testing, paired with a skilled functional medicine practitioner who is well-versed in mold-related illnesses, can make all the difference when you’re trying to get better. They can then create a detailed, tailored plan to remediate your body of mold and mycotoxins and improve your gut and immune health.

Ready to support your gut? We can help
Mold and mycotoxins can wreak havoc on gut health, and it’s important to test not only the environments you frequent the most but your mycotoxin levels as well.
By learning more about your conditions and the reasons they developed, you can take proactive steps toward enhancing your digestive health, whole-body health, and overall quality of life.
Are you ready to learn more about your gut health and how to improve your digestive health? Read more on our blog about gut health, or schedule your free 15-minute consultation with Dr. Paul to explore a personalized approach for a helpful and effective path to recovery.
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