Dientamoeba fragilis is a protozoan parasite.
It frequently comes hand in hand with another bug known as Blastocystis hominis.
As a human parasite goes it is reasonably prevalent with estimates of infection ranging from 0.4% to 42%. The interesting thing to note, especially when compared to other protozoan parasites, is the infection rate in developed countries.
Estimates put Dientamoeba fragilis infections at 9.4% in the US, 11.7% in Sweden and a whopping 16.9% in the UK (1).
In the following article we will outline what Dientamoeba fragilis is, possible symptoms, routes of infection, standard care for elimination, and finally some alternative treatment options to explore.
As a side note: This is a parasite that I have personal experience with. I found the infection, along with a number of others (Blastocystis hominis, Klebsiella and Citrobacter) after consuming unfiltered rain water while living in the Byron Bay area of Northern NSW.
What Is Dientamoeba Fragilis Anyway?
As mentioned above Dientamoeba fragilis falls into the protozoan phylum. This makes it a single celled eukaryotic organism.
Dientamoeba fragilis was first described in 1918 by two scientists Jepps and Dobell. Until that point three other amoeba like organisms had been discovered, Entamoeba coli, Entamoeba nana, both considered harmless by many and Entamoeba histolytic, considered pathogenic and responsible for amoebic dysentery (2).
Dientamoeba fragilis was quite different in form and function that a whole new genus was created to classify it.
Two particular things make Dientamoeba fragilis different.
One that it is fully mobile and two the lack of a cyst stage of development (3).
The ability to form cysts is of paramount importance for many pathogenic microbes. Without that particular ability Dientamoeba fragilis cannot survive outside of a host (in the external environment.) Hence the name fragilis.
It is something that has baffled scientists and researchers for awhile now and although there has been mention of cyst formation it has still not been properly verified.
To some this point may seem trivial but the lack of a cystic stage of development excludes the fecal-oral route of infection (a very common route of infection for most parasites)
The other issue around the question ‘how did I become infected with Dientamoeba fragilis?’ is that this particular bug probably doesn’t have the ability to survive the stomach acid bath (one of our major defences against gut infections).
To prove his point, Dobell the same scientist that helped to discover the bug, actually consumed a culture with thousands of living Dientamoeba fragilis organisms! Dobell spent the next ten years inspecting his stools with no trace of Dientamoeba fragilis (4).
Is Dientamoeba Fragilis Really To blame here?
This is the million dollar question.
Some researchers and gut health clinicians think it is a parasitic infection that needs to be treated in anyone that presents with it. Some think that it is a commensal microbe that is simply blamed for poor gut health because it is easy to find on a cheap and readily available stool test.
It could be that certain strains of Dientamoeba fragilis are more pathogenic than others but the jury is still out here.
I think it is best to keep an open mind and not to blame Dientamoeba fragilis unless you have ruled out other possible gut disorders like small intestinal bacterial overgrowth, large bowel dysbiosis and even things like coeliac disease.
Symptoms of Dientamoeba Fragilis Infection
Dientamoeba fragilis infection presents with many of the same non-specific symptoms as many of the other GI infections.
Again keep in mind that other gut disorders may be causing your symptoms. Again, this is why it is important to work with someone who really knows the in’s and out’s of gut health. For support here you can book for a distance consultation with the clinic here.
Ok back to the symptoms that Dientamoeba may be causing…
- Recurrent abdominal pain in children
- Irritable Bowel Syndrome in adults (5).
- severe abdominal pain
- mild fever
- general fatigue (4).
There is even a paper published in 1983 that relates a case of ulcerative colitis (inflamed and ulcerated colon ie: large intestine) to an infection by Dientamoeba fragilis.
Treatment of the parasite subsequently cleared up the illness (6).
Route of Infection for Dientamoeba Fragilis
If Dientamoeba fragilis wasn’t enigmatic before here is where it really gets interesting.
The route of infection for many parasitic microbes is via the fecal-oral route.
To survive the external environment a parasite will form a cyst. This stage of development also prevents the pathogen from being killed in a healthy humans extremely acidic stomach.
As of yet it hasn’t been confirmed whether Dientamoeba fragilis can actually form a cyst and the general consensus is that it can’t. Another proposed route of infection is human to human, but again this is not a strong theory as Dientamoeba fragilis is actually quite fragile outside of the human bowel.
The last theory that seems the strongest involves the ova of Enterobius vermicularis a parasitic pinworm. Apparently the DNA from organisms very similar to Dientamoeba fragilis have been found “hitching a ride” in the pinworm (8).
Not a pleasant thought but there it is. Below is a close up of a pinworm (Enterobius vermicularis) egg that Dientamoeba fragilis may be hiding in.
So this theory seems to beg the question of the likelihood of a pinworm co-infection with many Dientamoeba fragilis infected individuals. Or possibly it could be the other way around. Perhaps you, or your family (remember pinworm infections are actually quite common in children) has had a previous Dientamoeba fragilis infection that you have successfully cleared. Only to find out later on that you have been reinfected with Dientamoeba fragilis again. If this is ringing true then I would recommend looking into whether anyone in the family has pinworms. If you do find them it is best to treat the whole family as they spread easily.
Testing for Dienatamoeba Fragilis
There are only two tests that I came across that would test for Dientamoeba fragilis. More on recommended gut testing here.
- The CDSA – comprehensive digestive stool analysis that actually cultures the stool sample and analyses it microscopically
- A PCR test – A polymerase chain reaction that tests the DNA in the stool sample
I have read that it is smart to combine the two and if you are suffering from any GI distress then why not cover your bases. There is nothing worse than a “false negative” meaning that you run the test and it actually misses the infection.
No test is perfect. Speaking of imperfect tests, if you do opt for a conventional stool test from your doctor be sure it is the PCR testing.
The culture based tests are incredibly unreliable.
If you are trying to save some money then why not run the tests that are covered by your healthcare and if nothing comes back then maybe move onto the more comprehensive (and expensive) functional medicine tests.
Below is an example of a PCR test showing both Deintamoeba fragilis and Blastocystis hominis infections.
Conventional and Natural Treatments for Dientamoeba Fragilis
Conventional medicine reaches straight for the antibiotics.
Apparently metronidazole (a favourite) has a high rate of failures/relapses reported by numerous studies (7).
Other conventional treatments include oxytetracycline, doxycycline, tinidazole, ornidazole and erythromycin (9).
As you may guess I am opposed to antibiotics unless they are absolutely and critically necessary. From what I have learned looking into antibiotics my personal opinion is strict avoidance unless absolutely necessary.
Many different human infections have developed a resistance to conventional medicines common antibiotic treatments. If one was to take the round of antibiotics and not 100% kill the infection (as happened to me) then you’re left with a disrupted gut microbiome, a compromised immune system and the presence of an opportunistic or pathogenic organism that can wreak havoc.
Alternative and Natural Treatments for Dientamoeba Fragilis
Functional Medicine approaches parasitic infections a bit differently than conventional medicine.
A functional medicine doctor may end up prescribing antibiotics (or referring to someone if they can’t.)
But before it comes to that there are a few essential steps to take.
- Remove all offending foods. The idea is to reduce inflammation in your stomach as much as possible. Things like sugar, refined foods, excess carbohydrates, gluten, grain and legumes as well as dairy are all possible offenders. It is advisable to eliminate these foods immediately!
- Replace your digestive enzymes and possibly supplement with herbal bitters, lemon juice, apple cider vinegar or even HCL to kick your digestion into gear. It is important to avoid HCL if you are taking steroids or NSAIDS. They damage your gut lining and adding HCL ontop can cause serious problems!
- The third step is to Repair a damaged gut lining. It might seem slightly odd to start into the repair phase before removing the offending organism but it is essential! It involves using things like bone broth, glutamine and other soothing herbs and nutrients to help with the gut repair.
- Next comes the killing phase (sometimes referred to as a weeding phase) See below.
- After the weeding phase a repopulation phase is necessary. Supplementing with pre and probiotics as well as fermented foods is essential!
- RETEST! It’s commonly advised to wait a few months before retesting.
Ok onto the antimicrobial herbs that have been effective in naturally treating Dientamoeba fragilis in the past.
Herbal Medicine for Dientamoeba fragilis
As always the scientific papers come up short on the herbal side. It is quite expensive to run proper trials (double blind placebo studies) and there is very little money in a natural supplement or herb that very few papers are published.
This may eventually resolve itself but for the time being we will have to rely on traditional herbal wisdom.
- Artemesia annua, aka Sweet Annie (14, 15).
- Black Walnut
- Oregano leaf and oil
- Herbs high in berberine (Coptis chinensis, Barberry, Oregon Grape Root)
As with many intestinal microbes the pathogenic nature of Dientamoeba fragilis is a debated topic.
Some researchers consider it opportunistic, only moving in and creating issues when there is a disrupted microbiome while other have committed it to the “confirmed pathogen” list (2).
This makes the decision on whether to treat it or not something to seriously consider. Personally, as with many GI tract infections, I would consider herbal treatment if you are experiencing any gut related symptoms listed above and have explored other issues that may be causing them (food allergies and intolerances being top of the list)
Work With A Gut Focused Herbalist
Oftentimes it takes looking at the whole picture when treating gut infections. I frequently see patients in the clinic who have tried a number of antibiotics, herbal medicines by the truckload and they still don’t feel better.
Over the years I have come to see good gut health as a complex ecosystem. We want to encourage the growth of our good bugs and selectively reduce the numbers of our bad bugs. At times it takes strong herbal antimicrobials. Other times you may only need a shift in your diet and a prebiotic supplement!
Need help with your digestion?
Hi, my name is Todd Mansfield. I am a clinical herbalist with a special interest in all things gut health.
If you are looking for digestive health support consider working with me. I see people online as well as in person from my clinic in Byron Bay.
Updated resource Herbal Medicine For Dientamoeba fragilis
An in vitro study looking into the effect of different dried plant extracts (garlic, pomegranate husk, goldenseal, black walnut, and two species of wormwood) found zero effect on the Dientamoeba fragilis cultures.
I’m not quite sure what to make of these findings but figured it was worth including to be thorough.
Also, I have recently come across some research on the effect of fresh, crushed garlic as well as pomegranate husk tincture on protozoal infections (giardia and blastocystis specifically).
Are you struggling with a parasite infection? Share your experience in the comments below. What has helped you?
References and Resources
- A review of the clinical presentation of dientamoebiasis
- Microbiology of Waterborne Diseases : Microbiological Aspects and Risks
- Dientamoeba fragilis the unflagellated human flagellate
- Emerging from Obscurity: Biological, Clinical, and Diagnostic Aspects of Dientamoeba fragilis
- History of antimicrobial use and the risk of dientamoeba fragilis infection
- Colitis Due to Dientamoeba fragilis
- Treatment of Dientamoeba fragilis in Patients with Irritable Bowel Syndrome
- The ambiguous life of Dientamoeba fragilis: the need to investigate current hypotheses on transmission
- A review of Dientamoeba fragilis carriage in humans Several reasons why this organism should be considered in the diagnosis of gastrointestinal illness
- Artemisinin and its derivatives in treating protozoan infections beyond malaria.
- Artemisinins: their growing importance in medicine
- Evaluation of the in vitro Antiprotozoal Activity of Various Dry Plant Extracts against Dientamoeba fragilis