Yeast, Clostridia and Viruses…

… And good bacteria!

A healthy digestive tract contains both yeast, clostridia, viruses and good bacteria.  The balance of good bacteria to other microbes plays an  important role in regulating inflammation, digestion and immune function.   

What is dysbiosis?

Dysbiosis is an imbalance in the natural flora of the digestive tract.  Bacteria in the gut has the potential to overgrow which creates inflammation, decreases nutrient absorption and, in the case of autism, impairs development.  The natural balance of good flora or probiotics in the digestive tract is essential to regulate immune function.  A lack of good bacteria or an overgrowth of unhealthy microbes can cause major problems for children with developmental disorders.


Bacteria live in the intestinal tract, sharing space with yeast. Antibiotic use makes creates the opportunity for yeast overgrowth.  Antibiotics kill both good and bad bacteria, but not yeast.  Children who have been on antibiotics many times without re-populating the digestive tract with good bacteria, will undoubtedly have issues with yeast overgrowth.  Many children are born with dysbiosis or imbalance in the gut flora because of C-section birth, IV antibiotics during birth and/or formula feeding, all of which contribute to yeast overgrowth.

Yeast live and feed on sugar.  Limiting high sugar (or foods that turn into sugar in the gut) is the first and most important step.

Signs of Yeast Issues


  • Demanding
  • Non-compliant
  • Aggressive
  • Stimming
  • Hands over ears
  • Chewing (on everything and anything) and teeth grinding
  • Laughing for no reason, in the middle of the night or spontaneously during the day
  • Climbing all the time
  • Standing on head or hanging upside down all the time
  • Brain fog: giddy super-silly behaviours
  • Loss of energy
  • Seeming out of it
  • Craving for bread, pasta and sweets

Clinical Signs:

  • Rashes
  • Eczema
  • Funky-smelling scalp (the “wet dog” smell)
  • Itching: perianal, genital and/or generalized
  • Redness: around the anus or vagina
  • Abdominal bloating
  • Increase in flatulence
  • Constipation or diarrhea
  • Change in smell of stool (yeasty, bready, foul or sweet)


Research by Dr. Sidney Finegold compared the gut flora of children with regressive ASD to neurotypical children.  The results show that clostridial counts were higher in the children with autism. The number of clostridial species found in the stools of children with ASD was greater than in the stools of neurotypical children. Children with ASD had 9 species of Clostridium not found in the neurotypical group.  The neurotypical group showed only 3 species not found in children with autism. In all, there were 25 different clostridial species found. In stomach and small intestine specimens, the most striking finding was total absence of Clostridia from neurotypical children and significant numbers of such bacteria from children with autism.

These studies demonstrate significant alterations in the upper and lower intestinal flora of children with late-onset ASD and may provide insights into the nature of this disorder.

Research by Dr. Derrick McFabe, at the University of Western Ontario, has explored aquired Clostridia infection and it’s relation to autism spectrum disorder.  In his study, rodents injected with propionic acid (from Clostridial species) displayed autism like behaviours including:

  • Spinning
  • Repetitive behaviours
  • Seizures / convulsions
  • Pushing away
  • Hyperactivity
  • Altered social interaction and impairment in “play” like behaviour

Here are some ways that Clostridia could play a role in autism:

  • Overgrowth of Clostridia species
  • Impaired immune activity
  • Damage to digestive tract
  • Nutrient deficiencies
  • Inflammation / Neuroinflammation
  • Impaired methylation
  • Depletion of glutathione
  • Damaged carnitine shuttles leading to essential fatty acid deficiency
  • Carbohydrate cravings


There is significant evidence that implicates altered immune function in autism, PDD, ADHD and other developmental issues.  Pre and post natal infection are known risk factors for ASD and many parents report the onset of autism symptoms after viral infection.

Viruses induce a response from the immune system.  The immune system response creates inflammation.  Research by Dr. Pardo, Dr Vargas and Dr. Herbert have shown definitively that inflammation plays a key role in ASD.  Dr. Pardo and Dr. Vargas examined the brain tissue of people with autism who had passed away.  Their findings showed an ongoing inflammatory process in the brain called NEUROINFLAMMATION. This research shows that autism is neurobiological in nature – that something impacting the body and brain is causing autism. The medical aspects of autism can be assessed and treated. If their are medical aspects to autism contributing to developmental delays and autistic behaviours, they can be treated and reversed.

Viruses can alter immune function contributing to:

Research has discovered that autistic children who had been exposed to certain viruses in the past showed high levels of antibodies to brain proteins, suggesting an autoimmune response.

It is well known that autism is caused by the interplay of genetic interaction with the environment.  Which genes and which environmental triggers is more difficult to understand because there are thousands of environments toxins and tens of thousands of genes in the human body. 

Early exposure to a virus can cause the body to mount an immune response that, in combination with environmental toxins, could go awry. In addition to producing antibodies against the virus, the body makes antibodies against itself, resulting in damage to tissues and organs. This is termed autoimmunity.

This “autoimmune” response is what happens in autoimmune diseases such as lupus, and some researchers think a similar response may account for the brain abnormalities found in people with autism, PDD, ADHD.

A study of 48 autistic children and 34 normal children and adults, the researchers measured levels of antibodies to two viruses—measles virus and human herpesvirus-6—in the subjects’ blood. These antibodies were chosen because they are often used in research on known autoimmune diseases.

The researchers also measured levels of two brain autoantibodies (antibodies to brain tissue).  One, anti-MBP, is an antibody to myelin basic protein, a protein found in the protective sheaths around nerve fibers in the brain. The other, anti-NAFP, is an antibody to neuron-axon filament protein, a protein that makes up the nerve fibers themselves.

How do you test Yeast, Clostridia and Viruses?

Laboratory tests can identify if your child has an overgrowth of yeast and clostridia species. There are a number of different test that can help assess your child’s microbiome.

Comprehensive Organic Acid Test:

The comprehensive organic acid test (OAT) is a urine test that tests for 48 strains of yeast and 22 strains of clostridia. The OAT test also evaluates mitochondrial function, brain chemicals like serotonin and dopamine, immunoexcitoxicity, nutrient deficiencies, toxic exposures, essential fatty acid metabolism and methylation impairments.

GI MAP – GI Microbial Assay Plus

The GI-MAP (Microbial Assay Plus) is unique type of comprehensive stool testing. It relies on quantitative polymerase chain reaction (qPCR) technology to detect parasites, bacteria, fungi and viruses by evaluating the specific DNA of the organisms tested. A microbial assay is the best test to evaluate for viruses.

Candida Albicans Immunoglobulins – IgM, IgM and IgA

Overgrowth of yeast can cause intestinal permeability and chronic inflammation. Conversely, candida overgrowth can develop when children have chronic inflammation and a “leaky gut”. While antibiotics are often lifesaving, the overuse of antibiotics and the addition of antibiotics to our food supply leads to gut dysbiosis.

Testing for the three immunoglobulin to Candida albicans, IgM, IgG and IgA, helps to identify immune how candida is impacting your child’s immune system. Once identified, candida species can be treated with dietary intervention, anti-microbial botanical medicines and probiotics which reduces inflammation in the body. When combined with gut healing treatment, the intestine is able to heal which regulates the immune system and helps to optimize brain function.

Microbes like yeast and clostridia can contribute to autism symptoms.