Although most fungi are harmless to humans, some can wreak havoc on our health, causing problems that range from thrush to infections in the brain.

A previous article detailing the findings of a recent study raised some intriguing questions about our complex relationship with fungi and their potential to cause us harm.

The study, by researchers at Baylor College of Medicine, found that a fungal infection in the brain produced effects similar to those seen in Alzheimer’s disease.

The fungus in the study was Candida albicans (C. albicans), and using animal models, the research team discovered how this common fungus enters the brain, activates mechanisms for its clearance, and generates amyloid beta-like peptides—toxic protein fragments thought to be central to the development of Alzheimer’s disease.

The findings highlight our complex relationship with fungus and raise additional questions about how those infections affect our health and their implications in neurodegenerative disorders like Parkinson’s, multiple sclerosis, ALS (amyotrophic lateral sclerosis), and Alzheimer’s.

A Bit About Fungi

So, what exactly are fungi, and how do they affect us?

Fungi are a group of spore-producing organisms that feed on dead organic matter and living organisms and include molds, yeasts, mushrooms, and mildew.

Fungi are not plants or animals and employ a unique method of survival—absorbing the nutrients they need from dead and living organisms. In the world of biology, fungi have their own category called a kingdom, separate from those of plants and animals—the kingdom of fungi. A recent assessment from Kew Royal Botanic Gardens estimates that this kingdom contains approximately 2.5 million species of fungi. Another source states that only about 60,000 of the known species have been described

C. albicans is a common fungus and has been found in the brains of people with Alzheimer’s as well as in those with other chronic neurodegenerative disorders. It’s a form of yeast present in the gastrointestinal tract, mouth, skin, and reproductive tract of most humans.

Most of the time, C. albicans is a harmless member of a healthy microbiome. However, it can also be responsible for infections ranging from superficial infections of the mucosa and skin to more serious infections affecting the blood, heart, bones, and brain. C. albicans can survive outside of the body and can colonize every human organ and tissue. It’s the most common cause of systemic fungal infections.

Dr. C. Orian Truss and the Yeast Connection

The relationship we share with fungi (and yeast in particular) and its connection to our health made a leap in 1978 when renowned cardiologist Dr. C. Orian Truss published an article called “Tissue Injury Induced by Candida Albicans: Mental and Neurologic Manifestations,” which appeared in the Journal of Orthomolecular Psychiatry.

As described in a 2016 article, Dr. Truss’s insight was that Candida albicans went beyond a superficial infection of the skin and mucous membranes and could cause a cascade of symptoms that included allergic and immune reactions that affected multiple organ systems—including the brain. This discovery, which he had observed in his patients, came at a time when a diet of refined carbohydrates was the norm, and the overuse of antibiotics and steroids by the medical establishment turned many patients into “yeast factories.”

Dr. Truss found that the combination of a low carbohydrate diet and the antifungal medication nystatin could reverse a wide variety of symptoms that included those from irritable bowel syndrome, skin conditions, allergies, and the extreme food cravings associated with obesity and pre-diabetes. Dr. Truss also found that mood disorders like anxiety and depression often improved in his candida patients. In 1984, he put his findings into print and published “The Missing Diagnosis.”

Another physician and contemporary of Dr. Truss was Dr. William Crook, who, although initially skeptical of Dr. Truss’ hypothesis, became a believer after one of his “stuck” patients saw Dr. Truss and experienced relief from many previously untreatable symptoms.

Dr. Crook began practicing according to Dr. Truss’s model, leading him to write “The Yeast Connection” in 1986.

Despite the work of Dr. Truss and Dr Crook, mainstream medicine largely rejected the concept of yeast and its negative impact on human health at the time. Almost fifty years later, much of their work has been vindicated, and many of their hypothesized connections have been proven correct.

Evidence Linking Fungi to Neurodegenerative Diseases

As mentioned in our previous article, several studies have found intriguing evidence that fungal infections are present in the central nervous systems of those with Alzheimer’s and not in healthy individuals who served as the controls.

In a 2022 review, researchers examined the role of fungus in central nervous system autoimmune and neurodegenerative disorders. The review states that, recently, increasing evidence has pointed to the role of peripheral fungi in triggering inflammation, immune response, and worsening of a range of noninfectious disorders of the central nervous system, including multiple sclerosis, Parkinson’s, and Alzheimer’s.

A 2015 study states that several researchers have proposed the possibility that Alzheimer’s may have a microbial cause. The researchers found evidence that tissue from the central nervous system (which includes the brain and spinal cord) of patients with Alzheimer’s contained fungal cells. These fungal cells were found in different regions of the brain, and researchers identified several species of fungus in their samples.

These fungal materials weren’t present in the control individuals who didn’t have Alzheimer’s. Interestingly, the study authors noted that fungal infection was also found in the blood vessels, which could explain the vascular pathology often found in Alzheimer’s patients.

Fungal Infections in the Brain

Dr. David Corry, a professor of pathology, immunology, and medicine at Baylor College of Medicine, is one of the original study’s authors, and his lab has years of experience studying fungi.

Even though Dr. Corry’s research has focused on mice, when asked how humans might acquire these types of fungal infections, Dr. Corry told The Epoch Times:

“Our work focused exclusively on the mouse, as you note, and the fungus Candida albicans. However, it has long been known that C. albicans commonly infects humans and likely has infected the entire species. In a subsequent publication, we will explore the issue of C. albicans brain infections of humans.”

Additionally, there is the question of how these infections get into the brain in the first place and across the blood-brain barrier, which protects the brain from invasion and infection.

“We show in our publication that C. albicans uses its secreted enzymes (proteinases) to essentially dissolve the proteins that keep the blood-brain barrier tight, allowing the fungus to enter the brain proper.” Dr. Corry said. “In more detail, we show that most or all of the secreted aspartic proteinases (Saps) secreted by C. albicans (total of 10) are involved in this, but by far the most important one is Sap2.”

In the original study from Dr. Corry’s lab, there was mention that the fungal infection in the brain could be cleared in ten days in healthy mice. When asked about this, Dr. Corry explained the process a bit further, telling The Epoch Times:

“When the fungus is injected intravenously into mice, as we do with our model system, they immediately go to many organs, but the brain is certainly one of the big ones. This initial infection is indeed cleared after 10 days and occurs by the actions of infection-fighting cells of the brain called ’microglia.’

“We showed two pathways that microglia detect C. albicans in the brain, allowing the microglia to attack and kill the fungi. Pathway 1 involves the secretion by C. albicans of a protein called candidalysin. Candidalysin is detected by a specific receptor on microglia (called Mac-1 or CD11b), triggering the activation of the microglia and turning them into C. albicans killing machines. Pathway 2 involves again the Saps. Saps break down a protein found in the brain called amyloid precursor protein (APP) into small fragments called amyloid beta (Ab) peptides. These peptides are detected by another receptor protein on microglia called Toll-like receptor 4 (TLR4) that also activates microglia to kill the fungi.”

Testing

Although Dr. Corry says that complete avoidance of infections by C. albicans is not possible, as C. albicans has, most likely, already infected the entire human species—he did say that it may be possible to eliminate C. albicans from humans—something he hopes to work on in the future.

Dr. Corry states that there are presently no tests for the presence of a fungal infection in the brain. In the meantime, however, there are ways to test if you have a fungal infection elsewhere and to test for the presence of mold in your home.

Dr. Jack Wolfson, a board-certified, now-holistic cardiologist and best-selling author, calls mold the hidden health crisis of the 21st century and believes it is at the root of the vast majority of diseases we face in the modern world.

Dr. Wolfson asserts that much of that mold exposure is from water damage in our homes—and that most homes have it. Although the connection between mold exposure and the most common diseases may not be one we usually think about, Dr. Wolfson believes the connection is there, telling The Epoch Times:

“As far as I’m concerned, every illness, whether it’s high blood pressure, cancer, brain disorders, heart attacks, strokes, blood clots, COVID, immune issues—living in a water-damaged home, contaminated with mold and/or bacteria is a contributing cause.”

If you suspect you may have mold in your body, Dr. Wolfson’s website offers a mold mycotoxin test. The test is a urine-based panel that tests for more than 30 different toxins that are released from the environment and food molds. Those with compromised immune systems are much more susceptible to fungal infections and may benefit from this type of testing to detect the presence of mold and help get to the root of their health issues.

If you want to test your home or workplace for mold contamination, Dr. Wolfson’s website also offers an Envirobiomics ERMI Mold Test, as well as a Swiffer Test for mold, actinomycetes, and endotoxins.

Final Thoughts

Fungi and humans have a complex relationship, and although most species are not harmful to us, some are. Fungi also have many beneficial uses and are used to create a variety of common medicines, like antibiotics (penicillin), which have saved countless lives. They are essential for helping grow fruits and vegetables and making many of our favorite foods like bread, wine, and cheeses. More research is needed to discover the implications of fungal species on our health and the etiology of specific diseases, as it may offer unique ways to treat the health challenges we face now and in the future. More research may also help us learn ways to navigate our ongoing relationship with this group of ancient organisms.