Ottawa Functional Medicine – Dominick Hussey – Centretown and North Gower
MCAS - Symptoms, Causes, Diagnosis and Treatment - Dominick Hussey

Mast Cell Activation Syndrome – Symptoms, Causes, Diagnosis and Treatment

Mast cell activation syndrome (MCAS) is a type of mast cell activation disorder (MCAD).

MCAD is the term for describing the whole spectrum of diseases of the mast cell.

There are two main types of primary mast cell diseases including:

  1. Mastocytosis – A rare mast cell activation disorder caused by the presence of too many mast cells and mast cell precursors. People affected by mastocytosis are susceptible to itching, hives, and anaphylactic shock, caused by the release of histamine from mast cells.
  2. Allergic-type phenomena –  Like allergies, urticaria, angioedema, and anaphylaxis.

There is a third type of MCAS where we observe inappropriate activation of the mast cells, where we cannot describe it as either Mastocytosis or an allergic-type phenomenon. We label this type of MCAD under the MCAS banner.

Read on to learn about the symptoms, diagnosis, causes, testing and treatment of MCAS.

What are the typical symptoms and systems affected by MCAS?

MCAS may affect virtually any system in the body. So by definition, MCAS may cause a multitude of different symptoms.

Neurological System

Neurologically, you may see symptoms of fatigue and cognitive dysfunction that a lot of people describe as “brain fog.”

There may be a motor and sensory neurologic issues.

And if the central nervous system is affected, there could be psychiatric issues including anxiety and depression.

Cardiovascular system

MCAS may affect the cardiovascular system with all sorts of autonomic related issues including:

  • Variability in pulse and blood pressure
  • Palpitations or Tachycardia or increased heart rate

Musculoskeletal system

MCAS may cause a lot of muscle pain, which is diffusely migratory. There may also be bone issues including osteopenia and osteoporosis.

Gastrointestinal (GI) System

MCAS can cause all sorts of issues in the GI tract including acid reflux, nausea, vomiting, and alternating diarrhea and constipation.

The Skin

We find mast cells predominantly at environmental interfaces on the outside of the body where they’re best positioned to serve out their principal role and defence. As such we see many skin issues with MCAS including rashes as well as nail and hair problems.

When you think about the biology of this, where do mast cells reside in the body? Well, there are present in every vascularized tissue, but they dominantly site themselves at the environmental interfaces and also perivascular sites. So that’s

Respiratory System

The lungs are another example of an environmental interface found in the body. As such, patients with MCAS can describe intermittent problems with shortness of breath, and sometimes wheezing.

Genitourinary (GU) System

The GU tract is another environmental interface. So MCAS patients may experience irritation and pain in the urinary tract.

Immune System

MCAS can reduce the function of the Immune system so leading to a wide range of possible consequences, including:

  • Increased susceptibility to infection
  • Increased difficulty with healing from infections and wounds
  • Increased risk for malignancies
  • Increased risk for autoimmune disease

We could go on to the other systems in the body, but I think you get the point that it’s just a bewilderingly vast array of potential symptoms.

Diagnosis of MCAS

The sheer number of different symptoms and the fact that each person can have different symptom picture makes diagnosing MCAS extremely difficult.

According to MCAS expert Dr Lawrence Afrin, most patients who are ultimately found to have MCAS have been searching for help with their symptoms for a very long time, typically for decades.

Cause of MCAS

At present, there are no scientifically validated cause for MCAS only possible theories.

One theory originates from researchers at the University of Bonn Germany. They suggest that MCAS patients may have mutations in the controlling elements of the mast cells. This opinion has not yet been verified so we more research to understand the cause better.

Testing for MCAS

Currently, there is no single reliable laboratory test available for the diagnosis of MCAS. There are some tests available that collectively give a good indication of MCAS.

  • Serum Tryptase – Measuring tryptase levels in the serum can be very helpful in diagnosing mastocytosis. We usually see tryptase levels elevated at least double the upper limit of normal and quite often much higher than that in mastocytosis. However, in MCAS, tryptase is usually normal. Or if it is elevated, it’s just very slightly raised. So it is undoubtedly a good idea to check a serum tryptase when looking for MCAS.
  • Serum Chromogranin A – Chromogranin A (CgA) is a protein released from neuroendocrine cells. These are cells that secrete hormones in response to signals from the nervous system. When measuring serum CgA, you must rule out that the patient does not have heart or renal failure, has not taken proton Pump Inhibitors in the last three days and does not have neuroendocrine cancer. If you have ruled out all the above, then an elevated CgA level is a good indication of MCAS.
  • Plasma and Urine Prostaglandin D2 – Prostaglandin D2 is a significant prostaglandin produced by mast cells.
  • Plasma heparin – Heparin is a compound occurring in the liver and other tissues that inhibits blood coagulation. According to Dr Lawrence, Afrin plasma heparin is a helpful, sensitive and specific test for MCAS.
  • 2,3-Dinor-11beta-prostaglandin F2 alpha – 2,3-Dinor-11beta-prostaglandin F2 alpha is a metabolite of prostaglandin D2.
  • Urine Histamine
  • Urine N-methylhistamine
  • Urine Leukotriene E4

Treatment of MCAS

Because of the complicated nature of MCAS, I recommend a simple step by step approach to treatment.

Step one: Identify and avoid the triggers

Before looking for the underlying cause of MCAS, it is vital to reduce any symptoms. The first part of this is to identify and withdraw any triggers. Typical triggers include high histamine foods so following a low histamine elimination diet is useful. A low Fodmap diet may also be worth trying as it has been shown to lower histamine levels in the body. For my clients, I tend to start with the low Fodmap diet. If symptoms do not reduce to a manageable level, then we try a low fodmap low histamine diet.

Step two: Identify an optimal antihistamine regimen

The second part of controlling symptoms is to find an optimal antihistamine regimen. There are two types of antihistamines you can try, medications and supplements.


If symptoms are severe, it may be necessary to use antihistamine medications. There are two types of antihistamine medications, H1 and H2 blockers.

H1 Blockers

H1 antagonists, also called H1 blockers, are a class of medications that block the action of histamine at the H1 receptor, helping to relieve allergic reactions. There are two types of H1 blockers, sedating and non-sedating. Since fatigue is such a common symptom in MCAS, it is better to use a non-sedating kind of H1 blocker. Examples of non-sedating H1 blockers include Allegra and Claritin.

H2 Blockers

H2 antagonists, sometimes referred to as H2RA and also called H2 blockers, are a class of medications that block the action of histamine at the histamine H2 receptors of the parietal cells in the stomach. They are typically used to reduce the production of acid in the stomach. Examples of H2 Blockers include Pepcid and Zantac.

When treating MCAS, you will often need a combination of an H1 and H2 blocker. There is no easy way to find the right combination except through a patient step by step trial and error approach. At this point, I would highly recommend you try this under the supervision of your doctor or trusted healthcare practitioner.

Natural Antihistamines

Natural antihistamines that have been shown to reduce histamine levels in the body include:

Step Three: Identifying and treating the cause

As I mentioned above, there is no known cause fore MCAS only theories.

In my clinical practice, I see a strong association between the presence of SIBO and excess histamine. This observation may explain why a low fodmap diet can be a useful tool for reducing a high histamine body load and reducing symptoms.

Regarding cause, I see some parallels with MCAS and true Fibromyalgia. Research has shown a possible link between fibromyalgia and childhood trauma. There has also been some research looking at an association between histamine and stress.

Based on the above observations I suggest a two-step approach for looking at the underlying cause of MCAS.

Step One – Looking for Infections

Assuming that we have already removed any food triggers from the diet then the next step would be to look for any gut infections in particular SIBO. You can do this by using a Lactulose Breath Test.

Step Two – Identifying and Resolving any Past Emotional Traumas

There are some treatment modalities that I recommend and may help with past emotional trauma, some are scientifically validated and some not.



Energy Healing


Mindfulness Training


This article is not intended to provide medical advice, diagnosis or treatment.

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5 Complications of SIBO - Dominick Hussey - Functional Medicine

5 Complications of SIBO

You will not die from SIBO, but it does lead to various complications. The main complications of SIBO include:

  • Nutrient Deficiency and Excess
  • Malabsorption
  • Increased Small Intestinal Permeability
  • Autoimmunity
  • Blunted Small Intestinal Villi

Read on to learn about the complications of SIBO occur in the body.

Vitamin B12  Deficiency

SIBO is known to cause a B12 deficiency in the scientific literature. Vitamin B12 deficiency happens in SIBO as a result of utilisation of the vitamin by bacteria. When bacteria take up the vitamin, the bacteria partly metabolise it to inactive analogues, which compete with normal vitamin B12 binding and absorption.

Symptoms of B12 deficiency may include things like neuropathy, cognitive decline, or even dementia.

There is a high prevalence of SIBO in the elderly. This fact could make you question whether the B12 deficiency seen in the elderly is related to SIBO and not just “ageing.”

Fat Malabsorption

SIBO can also cause fat malabsorption, which leads to a buildup of free bile acids. A build-up of bile leads to mucosal inflammation can lead to increased intestinal permeability. Increased intestinal permeability aka leaky gut can lead to autoimmunity.

Fat malabsorption can also lead to a decline in the absorption of fat-soluble vitamin including:

  • Vitamin D and K2 which will cause osteoporosis
  • Vitamin A which will cause night blindness and retinopathy
  • Vitamin K leading to prolonged clotting times

Stunted Small Intestinal Villi

SIBO can lead to blunted small intestinal villi that will decrease the activity of disaccharides. Disaccharides are enzymes that are required to break down carbohydrate.

A reduction in disaccharide activity will lead to carbohydrate malabsorption. Carbohydrate malabsorption will lead to a build-up of carbohydrates in the small intestine. The bacteria in the small bowels feed on carbohydrates.

So blunted intestinal villi will lead to increase the number of bacteria so worsening the SIBO.

Protein Malabsorption

Bacteria digest protein. When you have too much bacteria in the upper part of the small intestine, where the protein is absorbed, then that will interfere with your absorption of protein.

Excess Folate

While B12 deficiency is prevalent with SIBO, folate levels can often be high in SIBO because of increased synthesis of folate by small intestine bacteria.


This article is not intended to provide medical advice, diagnosis or treatment.

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3 Primary Causes of SIBO - Dominick Hussey

3 Primary Causes of SIBO

The causes of SIBO or Small Intestinal Bacterial Overgrowth and how it develops is not entirely clear, and it’s still somewhat debatable. SIBO begin when there is a disruption in the mechanisms that control the number of bacteria that live in the small intestine. There are at least seven risk factors that are potential causes for that disruption.

  • Structural or anatomic issues, for example, after surgery, if there was damage to nerves that enervate the small intestine, or patients with Cystic Fibrosis
  • Motility disorders, so dysfunction of the migrating motor complex
  • Irritable bowel syndrome
  • Metabolic diseases like diabetes
  • Low stomach acid
  • Age
  • Organ system dysfunction
  • Medications

The 3 Primary Causes of SIBO

According to Chris Kresser, Functional Medicine and SIBO expert, three primary processes cause SIBO:

  • Low gastric acid secretion
  • Small intestine dysmotility
  • Disrupted microbiota

Low gastric acid secretion

Stomach acid suppresses the growth of ingested bacteria, which would limit bacteria in the upper small intestine. For this reason, hypochlorhydria, or low stomach acid, is a primary risk factor for SIBO.

Low stomach acid can develop:

  • When H. pylori bacteria are present
  • With chronic stress
  • As a consequence of ageing

There are also drugs that inhibit acid secretion, like histamine type 2 receptor blockers, and Proton Pump Inhibitors, both of which are used to treat heartburn and GERD.

If a person has heartburn and they take these acid-suppressing drugs for a significant period, it reduces stomach acid it may predispose them to develop SIBO.

Small intestine dysmotility

The next primary of the causes of SIBO is impaired intestinal motility or dysfunction of the migrating motor complex (MMC). The MMC sweeps residual debris through the gastrointestinal tract so abnormalities in the MMC may predispose to the development of SIBO.

Disrupted microbiota

The third of the primary causes of SIBO is a disrupted gut microbiome, but there is less research on this proving a direct cause. There are however several lines of evidence that support an association.

One is that it’s well-established that antibiotic use can lead to disrupted gut microbiome and in turn SIBO.

Celiac disease also leads to a disrupted gut microbiome, and there’s a definite connection between celiac and SIBO.

Disrupted gut microbiome has been shown to cause dysfunction of the ileocecal valve, and we know that dysfunction of the ileocecal valve can lead to translocation of bacteria that should stay in the large intestine into the small intestine, which is one of the principal ways that SIBO develops.



This article is not intended to provide medical advice, diagnosis or treatment.

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What is the Correct Definition of SIBO - dominick Husey

What is the Correct Definition of SIBO?

There are several different definitions of small intestinal bacterial overgrowth (SIBO). Part of the challenge of dealing with it is that there isn’t even really a consensus on how to define it. On the simplest level, it indicates the presence of excessive bacteria in the small intestine. But what is the correct definition of SIBO?

In this article, I discuss the different ways parameters or measures scientists have explored (at the time of writing) to find a correct definition of SIBO.

The Number of Bacteria

A more specific definition of SIBO is where the number of bacteria in the small intestine exceeding 105 to 106 organisms per millilitre. Usually, there should be less than 103 organisms per millilitre found in the upper small intestine, and the majority would be gram-positive. But this specific definition of SIBO relies on endoscopy, which is one of the two test methods used to detect SIBO, but it’s the least frequently used. In fact, I can not think of any Functional Medicine practitioner, that is using endoscopy to diagnose SIBO, so it’s not that helpful of a definition for our practical perspective.

The Type of Bacteria

In addition to the absolute number of bacteria in the small intestine, the type of flora also plays a role in the signs and symptoms of SIBO. The predominant bacteria metabolize bile salts to unconjugated or insoluble compounds, and that can cause fat malabsorption or bile acid diarrhea.

Microorganisms that preferentially metabolize carbohydrates to short-chain fatty acids in a gas can cause bloating without diarrhea. Whereas gram-negative bacteria that are overgrown in the small intestine like Klebsiella can produce toxins that damage the mucosa and interfere with nutrient absorption.

This explains why people with SIBO can have such a wide range of symptoms. It depends on which type of bacteria is overgrown in the small intestine. Again using the type of bacteria found in the small intestine to define SIBO relies on endoscopy.

Measuring Gases

The two main ways of testing for SIBO is through an endoscopy of the small intestine and a lactulose breath test. As mentioned above the former method is not practical. The breath test measures the quantity of hydrogen of methane produced in the small intestine. This method is relatively straightforward but there is no consensus on how to interpret the results. This lack of consensus makes it difficult to establish a firm definition based on the results of a breath test.


So what does this mean? There are three possible measures you could use to define SIBO: the number of bacteria, the type of bacteria and the gases produced in the small intestine. Using any of these measures to establish a correct definition is made difficult because of the limitation of the two main testing measures. It is my observation that currently, the majority of Functional Medicine practitioners (including myself) use the more practical breath test results to diagnose SIBO.



This article is not intended to provide medical advice, diagnosis or treatment.

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3 Overlooked Causes of GERD - Dominick Hussey - Functional Medicine

3 Overlooked Causes of GERD

According to the Canadian Society of Intestinal Research, 13% of Canadians suffer from Gastroesophageal Reflux Disease (GERD). This figure may be much higher because of the vast majority of people that experience GERD self-medicate. But what are the causes of GERD? Read on to learn more about this common disease and three overlooked causes of GERD.

What is Gastroesophageal Reflux Disease (GERD)?

GERD is when the contents of the stomach go up the oesophagus and into the throat.  The symptoms of acid reflux include:

  • Acidic taste in the mouth
  • Burning pain in the chest
  • Vomiting
  • Breathing problems
  • A chronic cough
  • Chronic laryngitis
  • Erosion of the teeth in longstanding issues

It is important not to ignore GERD as it may lead to chronic inflammation of the esophagus (Barrats Esophagitis) and even esophageal cancer.

What are the medical causes of GERD?

Medical textbooks describe the cause of GERD as a dysfunction of the lower esophagal sphincter that usually prevents the stomach acid from travelling from the stomach and up to the esophagus.

The medical treatment for sphincter dysfunction is surgery known as a Fundoplication. Surgeons wrap the upper part of the stomach around the lower part of the esophageal sphincter.

Like medication, the use of surgery is trying to treat symptoms and is not resolving the underlying causes of GERD.

What are Underlying Causes of GERD?

When looking for the cause of any health issue, it is best to take a simple step by step approach. This approach means looking for the most straightforward reason first.

1. Think of Diet First

If you suffer from any digestive issue including GERD then looking at your diet is an excellent first step.

Following an elimination diet, whereby most food allergens are removed, is an excellent place to start. Most elimination diets exclude wheat, dairy, spicy foods and nightshade vegetables.

Examples of elimination diest include:

The underlying cause of GERD may be Irritable Bowel Syndrome. Their symptoms are very similar. A low fodmap diet has been shown in clinical trials to help symptoms of IBS.

2. Dysbiosis

If the elimination diet does not give 100% relief, then the next consideration is dybiosis. Dybiosis is an imbalance or overgrowth of bacteria that live in the gut. Two types of dybiosis are associated with GERD.

H.pylori Overgrowth

H.pylori is a type of bacteria that live in the stomach and have been shown to be a cause of stomach ulcers. If someone has GERD and an overgrowth of H.pylori then it would seem reasonable to treat the H.pylori.

You can test for H.pylori using a stool, breath and blood test. Using a combination of all three tests ensures a more accurate diagnosis.

Small Intestinal Bacterial Overgrowth (SIBO)

SIBO can often be the underlying cause of IBS. It, therefore, makes sense that the treatment of SIBO may also help GERD.

SIBO can cause increased gas pressure in the small intestine and the stomach. This gas pressure may be one the mechanism by which SIBO causes GERD.

Reduced intestinal motility is associated with SIBO and may also contribute to GERD.

Testing for SIBO is achieved via a lactulose breath test.

Treatment of SIBO is a combination of a low fodmap diet, herbal antimicrobials and prokinetic supplements.

Prokinetics help with gut motility. Iberogast, a prokinetic, has been shown to relieve symptoms of heartburn and reflux. Another useful prokinetic supplement is Motilpro.

3. Increased Stomach Acid

If both dietary and dybiosis interventions do not give 100% relief, then the cause of GERD could be due to excess stomach acid.

The symptoms of high and low stomach acid often overlap however excess stomach typically occurs in younger people.

If younger people report a gnawing-type stomach pain or any family or personal history of gastritis or ulcers, there is a likelihood they are having issues with high stomach acid.

Treatment of increased stomach acid

In some cases, it may be necessary to use a take a short-term course of acid lowering medication.

Alternative treatments for increased stomach acid include a combination of Melatonin, B Vitamins, Betaine and Methionine.

Alternative treatments are not recommended for long-term use.

In Summary

Many Canadians suffer from GERD. The medical treatment of GERD is surgery.

3 often overlooked causes of GERD include diet, dybiosis and increased stomach acid.

If you think you have GERD then looking into these overlooked causes in a simple step by step approach may resolve your problems.



This article is not intended to provide medical advice, diagnosis or treatment.

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How Do Probiotics Work For Constipation and Gas - Dominick Hussey

How Do Probiotics Work For Constipation and Gas?

There is a growing body of evidence showing that probiotics help digestive symptoms. This evidence has anecdotal, clinical and research origins. But how do probiotics work?

One popular theory is that probiotics repopulate the gut. Scientific research has not currently proved this argument.

Another hypothesis is that probiotics help to rebalance the friendly bacteria by killing the harmful microbes.

Read on to learn about a recently published research study that shows how probiotics work for constipation and gas.

A recent study published in the PLOS One journal has shown that probiotics can help reduce gas and improve constipation by decreasing certain “unfriendly” bacteria in the gut. These unwanted bacteria included Citrobacter, Klebsiella and Methanobrevibacter.

The researchers recruited 21 healthy adults. Each adult took a probiotic mixture. The composition of the mix included five strains of Lactobacilli and two strains of Bifidobacteria. Each adult received the combination once a day for 60 days.

What the study found

At the end of the study, the researchers found that there was a significant reduction in the numbers of Citrobacter, Klebsiella and Methanobrevibacter bacteria. This decrease in bacteria coincided with a decline in gas and constipation.

More specifically the researchers were able to show that there was a direct association between the reduction in abundance of Methanobrevibacter, the decrease in flatulence (for all the adults) and a decline in constipation (for women only).

This finding is not a surprise as there is a close correlation between Methanobrevibacter species and constipation and the production of methane gas.

A frequently overlooked ability of probiotics is their antibacterial effect. Probiotics can produce antibacterial and antifungal peptides (chemicals) that help reduce bacterial overgrowth in the gut.

How Probiotics Work For Constipation and Gas

The researchers concluded that the probiotics work for constipation and gas through their antibacterial effect which led to the reduction in the unfriendly bacteria.

There have been many studies like this one that show that taking probiotics may help reduce digestive symptoms. These studies have used different types of probiotic species.

As well as Lactobacillus and Bifidobacterium there are two other classes of probiotics including Saccharomyces boulardii and Soil Based Probiotics.

Does it matter which probiotics you use?

The simple answer is no, but it does matter which particular probiotic supplements you buy.

When choosing a probiotic supplement, you should consider the following:

  • Make sure you purchase a high-quality scientifically tested product that is safe.
  • Be wary of marketing that claims that a product can help with specific symptoms.

If you do decide to take a probiotic, then listen to how your body reacts and ignore any purported claims. If you don’t feel any improvement or your symptoms worsen, stop that supplement and move on to the next.


This article is not intended to provide medical advice, diagnosis or treatment.

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Dysbiosis- #1 Overlooked Cause of Weight Gain - Dominick Hussey

Dysbiosis – #1 Overlooked Cause of Weight Gain

According to Statscan one in four adult Canadians are obese or carry excess weight. For some of these people, the cause of their weight gain is due to diet and lifestyle. For others, the reason seems less obvious. They eat well and do a right amount of exercise but still the pounds roll on. Some of these people visit their family physician for a medical explanation. Their doctor checks their thyroid but after testing that everything appears normal. Read on to learn about the #1 overlooked cause of weight gain that may be stopping you lose those unwanted pounds.

Dysbiosis – The Cause of Weight Gain for Susan

Susan, 44, came to me complaining of bloating, constipation, abdominal pain and weight gain. The digestive symptoms began one year previously shortly after a round of antibiotics. Her doctor gave the antibiotics for a chest infection. Susan had never before had digestive issues and so being health conscious went back to her doctor. Her doctor said that she was reacting to the antibiotics, which would resolve itself and in the meantime prescribed Laxaday (a laxative) for constipation and acetaminophen for the pain.

Susan took the medication for a month, but each time she tried to stop them her symptoms returned. Again she went back to her doctor who suggested she may have irritable bowel syndrome (IBS) and referred her to Gastroenterologist (GI) consultant for a proper diagnosis. After waiting two months for her appointment, she spent 10 minutes with the GI consultant who agreed with the diagnosis and advised her to manage her symptoms with her current medication. During the same consultation, Susan asked the consultant about some recent weight gain. She had put on 10 pounds in a month. The consultant replied that it was not their area of expertise and told her to ask her family physician.

Keen to find answers she went back to her doctor for an explanation for her weight gain. She told her doctor that her mother had a low thyroid and wondered whether that might be causing her weight gain. Her doctor agreed and sent her for blood work, but the results came back as normal.

For the next seven months, Susan put on another 20 pounds despite being careful with her calorie intake and increasing her exercise. Nothing would help, and she was becoming depressed about her weight. It was at this point after speaking to a friend who was a client of mine that she came to me for a functional medicine consultation.

As a functional medicine practitioner, I am trained to take a very in-depth case history and spend a long time (45 minutes) listening to our client’s story. This process allows me the best opportunity to identify the root cause of my client’s health issues.

After hearing Susan’s story, I told her that the cause of her weight gain might be the result of her poor digestion. More specifically I was suspicious she had dysbiosis.

Dysbiosis is an imbalance of bacteria that live in your intestines.

Research on Weight Gain and Dysbiosis

There is a growing amount of scientific evidence that there is an association between the makeup of the microbiota and weight gain. In studies of twins who were both lean and obese, researchers found that the thinner twin had a much more diverse microbiota compared to the fat twin.

The fact that we associate microbiota diversity with weight gain does not mean one affect the other – cause and effect. To demonstrate cause and effect researchers devised a novel experiment where they bred two same bacteria-free mice. Then they populated their guts with bacteria collected from obese women and their lean twin sister. The mice ate the same diet in equal amounts, yet the animals that received bacteria from an obese twin grew heavier and had more body fat than mice with microbes from a thin twin. As expected, the obese mice also had a less diverse community of bacteria in the gut.

In my practice, the #1 cause of dysbiosis is from medication most commonly antibiotics but also birth control medicine.

Dysbiosis is present in certain gut infections including small intestinal bacterial overgrowth (SIBO), candida and parasites.

To identify the cause Susan did a breath test for SIBO and a stool test to look for candida and parasites.

Susan was positive for SIBO.

To treat the SIBO, I put Susan on low FODMAP diet and various antimicrobial supplements to help balance and reduce her bacteria.

After two weeks, Susan reported 90 percent improvement in her digestive symptoms. After four weeks, she had lost 8 pounds. After ten weeks she had lost a further 10 pounds.

After 15 weeks her SIBO was gone (after retesting), and she was back to her healthy weight.

Susan was, of course, was thrilled and at the same time was amazed how treating her digestion had reversed her weight gain.


This article is not intended to provide medical advice, diagnosis or treatment.

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An Overlooked Way To Test For Vitamin D - Dominick Hussey

An Overlooked Way To Test For Vitamin D

Vitamin D is critical for health. It promotes calcium absorption in the gut and helps maintain calcium and phosphate levels in the blood. This, in turn, enables proper bone health and protects against osteoporosis, rickets, and fracture; but it also plays a number of other important roles in the body, including regulating cell growth, neuromuscular function, and immune function. So using an accurate measure to test for vitamin D is important.

The most common blood marker used to determine vitamin D status is 25(OH)D, and the reference range for this marker in the United States is 30 ng/ml to 100 ng/ml. This converts to 75 nmol/l to 250 nmol/l in Canada.

The problem with this range is that 25-D is not the biologically active form of vitamin D and is thus not the best marker for biological vitamin D activity. That means it’s possible for someone to have a normal 25-D level and still be biologically deficient.

In this article, I’m going to talk to you about an often overlooked lab marker, parathyroid hormone, or PTH, which more accurately diagnoses vitamin D deficiency. Armed with this information, you will better equipped to test for vitamin D deficiency.

How I discovered PTH?

I learned about using PTH to test for vitamin D while doing some training with Chris Kresser, a Functional Medicine Practitioner and one of the sharpest people I follow in the functional medicine space.

Why use PTH to test for Vitamin D?

The conversion of 25-D, the inactive form of vitamin D, to 125-D, or calcitriol, the active form, is tightly regulated by parathyroid hormone. Parathyroid hormone increases calcitriol formation and thus increases serum calcium by acting on the kidneys and bone. Generally speaking, PTH levels will be high when vitamin D is low, since the body is producing more PTH to increase calcitriol formation, and PTH levels will be low when vitamin D levels are sufficient because of negative feedback of vitamin D suppressing PTH output.

What is an optimal range for PTH?

The typical PTH lab reference range is between 10 and 65 pg/ml. That’s what’s considered normal.

A study of vitamin D-suppressing effects of PTH showed the greatest effect when PTH was over 49. In that situation, taking vitamin D reduced PTH by 21 pg/ml. With PTH at a baseline of 38 to 49, taking vitamin D reduced PTH by 17 pg/ml, and with a baseline, PTH of 6 to 38, taking vitamin D only dropped PTH by 2 pg/ml.

So what does all of this mean?

If you have a 25-D level of 35 ng/ml (87 nmol/l), that would technically be normal according to the reference range. But if your PTH is 50, you can be fairly certain that you are biologically deficient despite having a normal 25-D level.

If your PTH is 35, it’s less clear, but since her 25-D is at the bottom of the range, supplementing with vitamin D until your PTH drops below 30 is probably still a good idea in those situations.

Why would a person with normal 25-D levels be biologically deficient?

We now know that there are several factors that affect the biological activity of vitamin D. These include:

  • Ethnicity and genetics, which impact the conversion of 25-D (the inactive form) to calcitriol, or 125-D (the active form);
  • Inflammation and obesity, which reduce the conversion of sunlight to vitamin D; and
  • Gut health, which affects the absorption of orally consumed vitamin D, among others.

These factors can sometimes explain seemingly unusual findings like seeing someone with a 25-D of 112 nmol/l, which is well within the normal range, but then a PTH that’s 55, which is well above 30, which is the level that indicates maximal suppression of PTH by vitamin D.

How using PTH helped a client?

I had one patient like this. He was overweight and had Rheumatoid arthritis. When I supplemented him with vitamin D and also got him more sun exposure, his 25-D went up to 150 nmol/l and his PTH went down to 32. I now include serum PTH in my basic blood chemistry work up with new patients because I find it so helpful in this regard.


Okay, let’s review what we’ve covered in this article.

25-D is the most commonly measured marker of vitamin D status, but it’s not a good indicator of biological vitamin D activity, and it can miss a lot of people who are deficient.

Serum parathyroid hormone reflects biological vitamin D activity and can be used to catch people who are deficient in vitamin D who would otherwise be missed.

A PTH level below 30 indicates that the patient is not deficient in vitamin D, whereas a PTH value above 30 suggests that the person may be biologically deficient even if their 25-D levels are in the reference range.



This article is not intended to provide medical advice, diagnosis or treatment.

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SIBO Die Off Symptoms and Treatment Reactions - Dominick Hussey

SIBO Die Off Symptoms and Treatment Reactions

When taking treating SIBO with either herbs or medication, you may experience SIBO Die Off symptoms. This phenomenon is known medically as a Jarisch-Herxheimer reaction, or “Herx,” for short.

Read on to learn about SIBO die off symptoms, why they occur, and the difference between die off symptoms and treatment reactions.

8 Common SIBO Die Off Symptoms

  • Fever
  • Muscle Aches
  • Chills
  • Headaches and Migraines
  • Rashes
  • Excess Mucus
  • Brain Fog
  • Increased Diarrhea, Constipation, Bloating and Gas

What is the cause of SIBO Die Off Symptoms?

This cause of SIBO die off symptoms depends somewhat on the specific mechanism of the herb or medication antimicrobials, but in many cases, the antimicrobials work by destroying the cell membrane of the bacteria.

When that happens, the bacteria release toxins known as lipopolysaccharides (LPS) into the intestines. If the lining of the gut
is permeable or leaky, the poisons will pass into the bloodstream.

The toxins will travel around the body resulting in the SIBO die off symptoms. This is the reason why you will often feel worse before they feel better or may alternate between feeling better and worse throughout the SIBO treatment protocol.

SIBO Die Off Symptoms Versus Treatment Reactions

Of course, not every adverse reaction to a SIBO treatment is a Herx response. In some cases, you may be reacting to the antimicrobial itself, perhaps a filler in the drug or a component of one of the supplements.

Unfortunately, it’s not always easy to determine the difference between a Herx and a reaction to the treatment, but there a couple of general pointers.

Herx reactions should pass or at least shift after a few days. You will start to feel better a few days after the die off symptoms, or you may alternate between feeling bad and feeling better than they felt before the treatment.

With a reaction to the treatment itself, patients usually feel bad continuously and do not improve even after several days or go back and forth between better and worse.

In my opinion, if you are experiencing SIBO treatment symptoms, it is crucial that you immediately discontinue treatment and contact the practitioner managing your case.



This article is not intended to provide medical advice, diagnosis or treatment.

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