Parasite Infections: The Mast Cell Activation connection

parasite infections and mast cell activation histamine intolerance

If you’ve been following these articles for some time you’ll know that I write about Blastocystis infections quite frequently

It isn’t a coincidence. I contracted this unpleasant bug a few years back and have tried a range of treatments from straight up antibiotics to multiple herbal antimicrobials protocols.

For some reason, and I know I’m not alone, certain Blastocystis infections are very recalcitrant and difficult to treat (4).  Let’s not leave out the Dientamoeba infection either. For me these two bugs have been impossible to clear.

I must say that the herbal antimicrobial protocols helped considerably. Containing a whole range of herbs including

After the herbal protocols I felt immensely better. So much so that I assumed I was clear and free of the parasite infections. Lo and behold, minor gut symptoms returned, mainly bloating after food. This is a good place to mention the essential importance of retesting after a treatment. If I had never retested I would still think that the bizarre and seemingly unrelated symptoms have nothing to do with Blastocystis hominis infection.

Update – After years of trying different herbal antimicrobial approaches I have managed to clear the two parasite infections and have learned a ton about the different herbs that work, which ones may negatively impact your beneficial gut flora and have formed some ideas on how long to take herbal medicine to get the best results.

Mast Cells

This brings me to the subject of this article. Mast cell activation in the presence of a gastrointestinal infection. When I first heard about mast cells and histamine intolerance my eyes glazed over and I lost interest in the white paper I was reading. Fast forward a year and I have certain unexplainable symptoms such as

  • Chronic sore throat
  • Sore lymph nodes just under my ears
  • Headaches
  • Fatigue and exhaustion
  • Bizzare food intolerances (more on that later)
  • Chronic sinusitis

Seeing as I didn’t have any gut symptoms I didn’t relate the upper respiratory tract issues with my gut infections. Then I heard a story from a practitioner friend who was treating a patient with the exact same symptoms plus a Blastocystis and Dientamoeba infection. So I decided to hit the literature and see what connections there might be.

Mast Cell Function

First off it is important to note that mast cells aren’t the problem here. One paper notes the beneficial immune functions these cells play in the human body that help maintain homeostasis including

  • Tissue repair
  • Angiogenesis
  • Innate immune function
  • Adaptive Immune function
  • Immune tolerance
  • Mediators of inflammation

“The strategic positioning of MCs at the interface between the host and the external environment near blood, lymphatic vessels, nerve fibers and a range of immune cells, including epithelial and dendritic cells, allows them to act as sentinels of invading microbes and respond rapidly to any change in environment by communicating with different immune cells” (7).

They have been described as sentinels, ready to deal with whatever comes their way. Definitely helpful allies but problematic when we keep triggering them into action.

mast cell activation parasite infection blastocystis dientamoeba byron bay gut health gut infection parasite

Image taken from Mast CellsPhenotypic Features, Biological Functions and Role in Immunity

In the picture above we can see that upon activation mast cells degranulate. This process involves the release of a whole range of different molecules including

  • Histamine – possibly the most important in our discussion
  • Cytokines – these are messenger molecules that can be pro-inflammatory or anti-inflammatory depending on their specific makeup
  • TNF – an inflammatory cytokine
  • Interleukins – 4,6 and 15 – yet another set of cytokine messenger molecules

Mast Cell Activation

How are these cells activated?

In the Fundamentals of Inflammation Joshua Boyce describes mast cells as a front line defence mechanism. As mast cells reside close to external environments such as the skin the airways and the gastrointestinal tract they are perfectly positioned to deal with incoming problems and degranulate, or release the contents listed above, in a range of different scenarios

  • IgE based allergies – proper allergic reactions that involve type 1 hypersensitivity. The most severe type 1 hypersensitivity is anaphylaxis
  • Pathogens
  • States of inflammation – an example here would be mucosal injury

While the first example of IgE based activation of mast cells is well understood and known for quite some time, the last two examples are worth more attention. Mast cell activation occurs from parasite infections (Blastocystis, Dientamoeba) and bacterial dysbiosis (Helicobacter, Klebsiella) as well as injured intestinal mucosa which is a consequence of such infections.

The resulting symptoms can be wide ranging and seemingly unconnected to a gut infection.

My symptoms included upper respiratory tract inflammation, headaches and extreme food sensitivities to histamine rich foods. Other symptoms of mast cell activation can include chronic/recurrent 

  • Flushing
  • Pruritus
  • Urticaria
  • Angioedema
  • nasal congestion 
  • Wheezing
  • throat swelling
  • Headache
  • Hypotension
  • Diarrhea

The list of symptoms comes from a review entitled Mast Cell Activation Disease and Microbiotic Interactions. The authors included an important point that all other disorders that could account for these symptoms need to be ruled out.

Take Home Points

Coming back to my personal experience I noted after a year or so of chronic Blastocystis and Dientamoeba infection there was a shift in symptoms from gut related (bloating, stomach ache, loose stools) to upper respiratory tract (chronic sinusitis aka blocked sinuses, sore throat, sore lymph nodes) all triggered from different foods. Cutting back on high histamine foods (coffee was particularly hard) has helped relieve the symptoms considerably but they aren’t gone by any means.

The link between mast cell activation and parasite infections is starting to be explored in the scientific literature (12,13,14,15,16). Understanding that many extra-intestinal symptoms may lead back to a gut infection is a key learning.

Proper gut testing is essential.

Are you suffering from symptoms that may be from mast cell activation? Leave a comment below.  

References and Resources

  1. Blastocystis hominis – A Protozoan Gut Parasite
  2. Blastocystis homminis – Probiotic Treatment
  3. Blastocystis hominis – Skin Disorders and Gut Infections
  4. Treatment failure in patients with chronic Blastocystis infection
  5. Stool Testing – My Personal GI Results CDSA + PCR
  6. Mast Cells and Anaphylaxis
  7. Mast CellsPhenotypic Features, Biological Functions and Role in Immunity
  8. Fundamentals of Inflammation
  9. Helicobacter Pylori – A Notoriously Popular Bacteria
  10. Klebsiella – Bacterial Dysbiosis, Detection and Treatment
  11. Mast Cell Activation Disease and Microbiotic Interactions
  12. IgE and mast cells in host defense against parasites and venoms
  13. Mast cells in allergy and infection: Versatile effector and regulatory cells in innate and acquired immunity
  14. Mast Cells in Gastrointestinal Disease
  15. The Role of Mast Cells in the Defence against Pathogens
  16. The Roles of Mast Cells in Parasitic Protozoan infections
  17. Recommended GI testing – CDSA + PCR
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  1. After losing a lot of weight almost 2 years ago after a heap of testing nothing was noted. But accompanying the weight loss was rashes around the eyes headache, fatigue and the feeling of tightness in neck. As well as irregular heart beat and all the other lovely stuff.

    After being plagued on and off and not feeling right for almost a year and a half slowly gained some weight back then was hit again with the same problems more testing to eventually confirm Dientamoeba.

    Haven’t explored antibiotics yet, doctor seems reluctant but life is miserable like this, and now depending on what I eat the symptoms of histamine intolerance get worse.

  2. Hi I’ve had blasto for 6 years and haven’t been able to test it with antibiotics successfully. I don’t eat gluten, dairy or sugar. But I do eat carbs, otherwise I’d be too weak. I’ve been diagnosed with MCA and POTS. However I beleive my gut infection is the root of all this. What was your protocol and how long did it take you. I feel I really need to get rid of this to be well again. Any advice would be a big help.

  3. Hello Todd,

    Thanks for sharing this article.I am happy that you resolved your issue. I was also tested positive with blastocytis and immensely sensitive to histamine containing and releasing foods.

    Would you elaborate your herbal antibiotic approach a little ?
    which of the herbal choices contributed most to your healing ?

    1. hey kaan, I have covered some of the herbs that helped shift my gut health back into balance here

      I’m not 100% positive that blastocystis is the issue in most people that have it. I think because it is easy to find on a cheap stool test that we blame it for other, harder to find, gut conditions. Things like SIBO, food intolerances and allergies and even large bowel dysbiosis should be on your radar, especially if you are struggling with histamine reactivity. The good thing is that all of the herbs that we use to treat blastocystis can help resolve bacterial overgrowth problems too.

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