Diagnosing mold illness with urinary mycotoxin testing?
If you’re dealing with chronic fatigue, digestive issues, autoimmunity, neurological and psychiatric illness, multiple unexplained or mysterious symptoms…mold exposure could be at the root of your illness.
Considering the possibility that mold could be making you sick, your next question might naturally be, “Okay, how do we figure out whether mold is the problem?”
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The educated guess of patients and doctors alike is usually the following: look for evidence of mold within the body. Kind of like when the doctor suspects you have a bacterial infection, they’ll collect a swab or blood sample to look for the potential pathogen in question.
It is possible to test mycotoxin levels in the urine. Some doctors use this as their main assessment tool for the diagnosis of mold illness. However, here’s the answer to the title of this blog post: urine mycotoxins cannot confirm or rule out mold illness as a cause of symptoms.
I’ll share with you why I disagree with the use of urine mycotoxin testing as the diagnostic criteria when I suspect chronic inflammatory response syndrome (CIRS), also known as mold illness, biotoxin illness, or sick building syndrome (SBS).
First…what is a mycotoxin?
A mycotoxin is a small molecule produced by mold that is capable of causing disease in humans and other animals.1 Mycotoxins are considered secondary metabolites, which means they are synthesized in order to become more competitive in the living environment. They are invisible to the naked eye, measuring as small as 0.1 micron (a micron = 1/1000 of a milimeter!).
Hundreds of different mycotoxins have been discovered. A single species of mold can produce multiple mycotoxins, and many mycotoxins are made by multiple species.2 Certain mycotoxins are known causes of hepatoxoticity (liver disease), nephrotoxicity (kidney disease), and carcinogenesis (cancer).
Mycotoxins are both directly toxic as mentioned but, as well as indirectly toxic through their ability to inhibit protein synthesis and mitochondrial function.
Various specialty lab companies offer methods through which to test the levels of a handful of common mycotoxins present in a urine sample. Some of the more common mycotoxins tested include aflatoxin, gliotoxin, ochratoxin, and trichothecenes.
Why does urine mycotoxin testing fall short?
Testing positive for urinary mycotoxins only tells us that you’ve been exposed to mycotoxins, and nothing more
Mold illness is triggered primarily by biotoxin exposure through inhalation. But exposure to mycotoxins can occur through routes of oral (ingestion), dermal (absorption through skin), and inhalation (breathing through the lungs). The presence of urinary mycotoxins doesn’t tell us where your exposure came from. And it doesn’t tell us how your immune system is responding to the exposure or how your body is processing the toxins. It’s not an accurate reflection of total body toxic load, and it’s not a marker of illness. It’s just confirmation that you have mycotoxins in your body.
Not everyone with mold illness will test positive for urine mycotoxins
Some people who are sick with CIRS test negative for urinary mycotoxins—called a false negative result. This means that a person who does indeed have mold illness tests negative for mycotoxins in their urine, despite mold and other biotoxins having caused their illness. What’s this about? Two possible explanations: 1) individuals with CIRS have impaired detoxification pathways which may contribute to low release of biotoxins through the urine, and 2) mycotoxins are not solely responsible for the onset of CIRS and are not the only biotoxin living within a sick building.
The punchline here is this: the absence of mycotoxins in urine does NOT rule out mold illness as a cause of symptoms.
The majority of humans will test positive for some level of mycotoxins in urine
The presence of mycotoxins in the urine does not confirm illness.
We are all exposed to mycotoxins through the foods we eat, and mycotoxins can remain in the body within blood and tissues for months after exposure. We cannot confirm to what extent urinary mycotoxins are excreted as a result of ingestion versus inhalation. A majority of people will actually test positive for urinary mycotoxins for this reason—but only a small fraction of those people are sick with CIRS. The presence of mycotoxins in the urine is not sufficient evidence to make a diagnosis of mold illness, despite what some clinicians claim. In medicine we often say correlation does not equal causation. It’s possible for a healthy person, with no signs of illness, to test positive for mycotoxins in the urine.3
Mycotoxins aren’t the only toxic byproduct of water-damaged buildings
Biotoxin illness cannot be blamed on mycotoxins alone. Our focus on mycotoxins as the sole cause of mold illness is far too narrow.
Products like bentonite clay and humic acid have been shown very effective at binding mycotoxins but don’t effectively decrease the inflammatory blood markers typically elevated in cases of mold illness. This is because the disease is caused by more than the mycotoxins alone.
Mycotoxins are just one of various biotoxins produced within a water-damaged building (WDB) environment. Exposure to other components of WDB such as actinomycetes, microbial VOCs, endotoxins, allergens, cell wall fragments, and spores can contribute to immune activation in the susceptible person. Simply measuring levels of mycotoxins provides a narrow and erroneous picture of what may be causing symptoms.
A leading researcher in the field of mold illness and the doctor who first discovered CIRS in 1997, Dr. Ritchie Shoemaker is vocal about his strong opinions discouraging the use of urinary mycotoxin testing for evaluation of mold-related illness—for many of the reasons described above.
Some practitioners disagree with Dr. Shoemaker, regularly using urine mycotoxin testing as a tool for both confirming the diagnosis and assessing the progression of treatment. I will describe below.
Well-known mold illness doctor Neil Nathan regularly employs urine mycotoxin testing when working with patients. When mycotoxins are found in the urine, he sees this as confirmation of mold illness diagnosis. Because many mold-sick patients have poor detoxification capacity and false negative mycotoxin testing, he will first prescribe a few days of glutathione and/or sauna therapy to provoke the release of toxins from the body, through the blood stream, and into the urine. After some duration of treatment for mold illness, he will then retest the patient’s urine mycotoxins. When this serial mycotoxin testing shows increasing urine mycotoxin levels, he claims that is evidence the body is successfully, finally, mobilizing toxins out of storage. When serial mycotoxin testing shows decreased levels compared to the initial test, this is his evidence that the treatment is working.
While Neil Nathan and other clinicians may have success using this diagnostic approach, it is never first step I take to diagnose mold illness—because of the many points I explained above. The presence of mycotoxins in the urine tells us about potential exposure to WDB, but reveals nothing about what’s happening within the patient’s immune system and how their body is uniquely reacting to those (and many other) biotoxins. We must assess physiology along with signs and symptoms to determine whether mold is causing illness.
How is biotoxin illness diagnosed, if not through assessing levels of mycotoxins in the the body? Stay tuned—this will be the topic of a blog in the very near future!