Understanding the Threats and Necessities from Mold and Mycotoxins

It is hard to imagine that any practicing Physician can dismiss mold or mycotoxins from a diagnosis when we realize the tremendous impact fungi and mycotoxins have on earth and our society. Fungi are a very resilient and powerful species.  While this newsletter focuses on the role mold and mycotoxins can play in moderate and severe chronic illness, a uniformed medical community can limit our ability to get the proper treatment.  Mold and mycotoxins can cause respiratory, allergic, and severe toxicities that can debilitate lives and can also cause death.  Understanding the environmental, medical, industrial and economic contributions of fungi informs us to the impactful presence mold and mycotoxins has on many elements of our lives.


Acknowledging the ubiquitous nature of fungi in our world and human biology also recognizes its resilience and critical role in life on earth.  After recognizing the powerful impact on life and industry, we can be respectful of the potential dangers of some molds and their byproducts. Mycotoxins, secondary metabolites of certain molds, are acutely toxic to our bodies and brains; however, other species and some of the same species of mold and mycotoxins contribute to our health, life saving medicine, nature, technology, and industrial innovation. It is important to understand the breadth of the population of fungi in the world to recognize that fungi are both friend and foe.

The Impact of Mycotoxins on Human Health

Mycotoxins produced by certain fungi are extremely dangerous to life.  These chemical byproducts of mold can be toxic to organ systems and can affect our immune system, motor function, cognition, mental capacities, and cause cancer or mycotoxicosis, a severely and potentially fatal infection.

Most homes today are constructed with manmade materials such as gypsum drywall and various types of plywood. When water damage or flooding occurs, these materials absorb and retain moisture.  As a result, certain mycotoxin-producing fungi can flourish mold-in-housewhen water damage from leaks, flooding, excessive humidity, and poor moisture control by HVAC systems occurs.  Some of the most common indoor mycotoxin-producing species of mold are Aspergillus, Penicilliums, Stachybotrys 1.and Cladosporium, which is common both indoors and out.  Each of these molds have numerous subspecies.  Different subspecies produce a variety of mycotoxins as well.

There are numerous estimates of the total number of fungi species that exist ranging from millions to billions.  The most recent estimate using modern DNA technology was made by (Microbiology Spectrum) and published in July of 2017. It states the number is between 2.2 and 3.8 million. Only around 120,000 species have been described by scientists to date.  There are approximately 300 known mycotoxins today using current technology.

There are very few studies on the neurotoxic effect of these mycotoxins as cases are randomly dispersed, and there are ethical issues with testing in humans.  Empirical evidence suggests that these mycotoxins get into the body most often by inhalation with the highest concentrations residing in the sinuses. The brain, which is adjacent to our sinuses, makes it especially vulnerable to mycotoxins. This is believed to be the cause of neurotoxicity and the cognitive dysfunction in patients with chronic fungal sinusitis. The irrigation of the sinuses during surgery of patients with cognitive dysfunction using Amphotericin B, a potent antifungal, often results in significant improvement and validates this assertion.


Important Roles Fungi Play in Ecology and Civilization

All life on earth is often described by the Five Kingdoms of Life. Fungi compose one of the five Kingdoms:  Plantae, Animalia, Fungi, Protista, & Monera.

Fungi in the Earth’s Ecosystem

An ecosystem is an area that can produce nutrients and sustain life.   Fungi contribute to the Earth’s ecosystem because they serve as the key decomposers and symbionts. For example, fungi reprocess nutrients for plants back into the ecosystem and unlock them from organic matter.

mold mycotoxins

Beautiful untouched virgin forest with pine trees and lichen. Norway

Plant life would starve without fungi, because, without these decomposers, nutrients would not be recycled back into the soil.  Some fungi live together with other organisms

where at least the fungi or the other organism benefit, or sometimes both. This is called symbiosis/mutualism.  An example is the role of fungi with algae to create the composite organism, lichen.  Lichens enable algae to live all over the world in many different climates. They also provide a means to convert carbon dioxide in the atmosphere through photosynthesis into oxygen, which we all need to survive. Lichens also have ability to absorb everything in their atmosphere, especially pollutants. Lichens provide food for animals, prevent soil erosion, and are used for monitoring pollution levels in our environment.

Fungi in our Microbiome (Gut)

The human microbiome consists of 10-100 trillion symbiotic microbial cells, primarily bacteria, in the gut. The microbiome also includes fungi, viruses, archaea, and protis.  Humans are dependent on this large population of microbes to stay alive.  A healthy microbiome protects us against germs, breaks down food to release energy, and produces vitamins.

mold symptoms allergies

The study of the fungal mycobiome is a new and rapidly emerging field that lags behind our understanding of the bacterial microbiome. The impact of the mycobiome on human health is significant, especially as overgrowth of specific fungal microbes can occur when the gut is compromised and is a potential factor in inflammatory diseases and metabolic disorders. More study is required to understand the positive impact of these fungal microbes, the purposes that they serve in a healthy individual, and how they interact with other bacteria and microbes.

The relationship between these microbes is symbiotic and synergistic; however, it can become competitive, if imbalanced.  Examples of imbalance include the emergence of fungal infections like vaginal yeast infections, thrush, or candida overgrowth that often result from antibiotic usage.  In these cases, the decreased bacterial count results in fungal overgrowth. A diet rich in sugars and simple carbohydrates can also result in candida overgrowth or exacerbate fungal infections in the body.

The Role of Fungi and Mycotoxin in Medicine

Most people have learned about Alexander Flemming’s discovery that the mycotoxin-producing fungi, penicillium, had an antibacterial effect that eventually resulted in the development of penicillin, the antibiotic in 1941.

Mold & Mycotoxins

Currently there are about 1,600 antibiotics commercially produced and a number of medical drugs that are manufactured using various fungi. Other examples of fungi-generated pharmaceuticals include anti-cholesterol statins and the human transplant enabling immunosuppressant, cyclosporin. Steroids such as cortisone and prednisone are also manufactured with the use of fungi.  In addition, fungi are used in the production of biotechnology medicines that are synthesized to be identical to the exact human proteins in our bodies. Examples include the pharmaceutical medicines insulin and human growth hormone (HGH).

The Role of Fungi in Food Production 

  • The oldest and best-known example is the use of yeasts for fermentation in brewing,Mold & Mycotoxins wine making and bread making. The alcohol biproduct of fermentation is technically a mycotoxin, although toxicity due to alcohol consumption is usually due to overexposure acutely or chronically.
  • Penicillium roquefortiiis infused in some cheeses to impart a strong and pungent flavor. Examples are Roquefort, Gorgonzola, Stilton Blue and Danish Blue. The white crust on the outside of the cheeses known as Brie and Camembert is the mycelium of Penicillium camembertii.
  • In the Far East, generations have developed a wide variety of interesting fermented foods, sauces and drinks, using fungi. Examples and the applicable fungi include koji (Aspergillus); miso, soy bean paste (Aspergillus); sufu, Chinese cheese (Rhizopus), nyufu or fuyu, bean cake or bean cheese (Rhizopus); shoyu or soy sauce (Aspergillus, Saccharomyces) and tempeh (Rhizopus).
  • Authentic soy sauce is fermented in a three-step process with the fungi Aspergillus oryzae and Zygosaccharomyces rouxii, as well as the bacterium Pediococcus halophilus.
  • Citric acid is an important preservative ingredient of sodas, other drinks, many candies, canned goods, baked goods, etc. It is too expensive to isolate the citric acid from citrus fruits, so it is produced in large-scale fermentation vats utilizing Aspergillus niger.

All of these fungi-produced and preserved foods are important to identify, study and understand, because they can be beneficial to the diets of healthy individuals and can contribute to a diverse and robust microbiome. But, for mold-toxic people or those with Candida overgrowth, these fungi-rich foods and additives can pose major problems and make them sicker and more toxic. It is a fine balance that we are only just beginning to understand.

The Role of Fungi in Industry

Fungi are able to break down plant cell walls and are used in the production of a wide variety of enzymes.

  • Enzymes are used to treat and modify fibers, particularly in the textile industry. Examples include stonewashed jeans, tanned leather, and paper products.
  • Enzymes are used to make food more edible or desirable by removing, adding or modifying components such as vitamins, nutritional elements, colors and flavors.
  • Enzymes provide a safe and sustainable alternative to the use of harsh chemicals in industry. Because enzymes work under moderate conditions, they reduce energy consumption by eliminating the need to maintain extreme environments, as required by many chemically catalyzed reactions. Reducing energy consumption leads to decreased greenhouse gas emissions.
  • Enzymes also reduce water consumption and chemical waste production during manufacturing processes.
  • Because enzymes react to specific situations and minimize the production of by-products, they offer minimal risk to humans, wildlife, and the environment.
  • End-product enzymatic material may be treated and used as fertilizer.


Recognizing the importance, resilience, and powerful attributes fungi displayed in our society can help us realize that these microbes are productive species and can have significant impact in any environment in which they reside.  This comes in strict contrast to environmental illness caused by the growth of mold or fungi from water damage or high humidity in indoor environments and the significant health issue posed for people who are consistently exposed to those conditions.  It is also important to recognize that in addition to the allergic reactions and immune response to mold, the mycotoxins produced by certain molds are a significant threat to our health and shouldn’t be underestimated.

The emergence of DNA sequencing technology has only become available since the 1990s and industrial applications of the technology is still emerging, but it is a major player in our continued knowledge and understanding of fungi. Therefore, it is understandable that many physicians educated in the past years to decades may not be as up to date on the harms and toxicities mold and mycotoxins in the environment can pose to human health. This is why I believe that a continued effort to study molds and mycotoxins and their impacts on human health is necessary and important. The more knowledge that can be gained about fungi as connections are made between forensic and new data, and the more that conclusive data and studies are published showing the ill health effects of water-damaged buildings and mycotoxin-producing fungi on human health, the more the wider community of physicians and medical practitioners will be equipped to properly diagnose and treat mold-toxic patients.

If you have questions, comments, or simply your story involving mold illness, please feel free to comment on this site

  1. Barbeau, Deborah N.; Grimsley, L. Faye; White, LuAnn E.; El-Dahr, Jane M.; Lichtveld, Maureen (2010-03-01). “Mold Exposure and Health Effects Following Hurricanes Katrina and Rita”. Annual Review of Public Health. 31 (1): 165–178.
  2. Bennet, J.W. ”Mycotoxins” Clinical Microbiology Review. 2003 Jul; 16(3): 497–516.