What is Blastocystis?

Blastocystis spp. infection- Blastocystosis

Blastocystis spp. is a group of parasites that is sometimes found in the lower intestine (large bowel). Infection with Blastocystis spp. is called blastocystosis. Blastocystis spp. is thought to be transmitted through oral-fecal contact from poor hand washing and hygiene practices, ingesting contaminated food or water, and exposure to animals.

Our understanding of Blastocystis has been revised several times. Up until 1996, Blastocystis was thought to be some type of yeast or fungi. It was only when Blastocystis DNA was studied that we realized it was a parasite. For a long time, we thought there was only one type of Blastocystis- Blastocystis homminis. We now know that there are actually 9 different subtypes, which are collectively called Blastocystis spp. 

There is still debate about whether Blastocystis spp. is even an infectious agent. This is because Blastocystis spp. can be found in the fecal specimens of many people who appear healthy and have no symptoms at all. There is a huge variation in the symptoms people experience, and how well treatment works. Why would there be such variation in symptoms and treatment response? Researchers suggest it is because of the different subtypes of Blastocystis having different effects in the body, and reacting differently to treatment.


Signs and symptoms of blastocystosis

In people who do experience symptoms, signs and symptoms can include:

·         Diarrhea

·         Constipation

·         Nausea

·         Vomiting

·         Abdominal cramps

·         Bloody stools

·         Bloating

·         Excessive gas

·         Anal itching

·         Loss of appetite

·         Weight loss

·         Dizziness

·         Headaches

·         Depression

·         Fatigue

·         Rash

Diagnostic considerations

At The Health Lodge, if we suspect you have blastocystosis, we may be interested in performing some tests to give us more information. These include:

·         Testing for Blastocystis spp. A common method to test for Blastocystis spp. is by stool culture, however we prefer to use a variation on this method that involves extraction of DNA followed by polymerase chain reaction (PCR) testing. This is considered the most sensitive testing method.

·         Screening for nutrient deficiencies, as Blastocystis spp. can contribute to nutritional deficiencies, especially iron.

·         Screening for food allergies and intolerances. We find that many of our patients with Blastocystis infection also have food allergies or intolerances. Blastocystis spp. has been found to increase the permeability of the gut wall, which allows large proteins that are usually broken down to pass through into the blood stream. These proteins can interact with the immune system and trigger a reaction.

·         We may be interested in screening for Blastocystis spp. in patients with irritable bowel syndrome or irritable bowel disease (Crohn’s disease, ulcerative colitis). Blastocystis infection has been associated with these diseases, and it may be an underlying cause or contributing factor in some cases.  

Treatment considerations

Common treatment for Blastocystis infection includes the antibiotic metronidazole (Flagyl). However, the high failure rates of eradication using single drug therapy has led to the use of combination therapies of multiple antibiotic and anti-parasitic medications. At The Health Lodge, we find the best results are often achieved with a combination of antibiotic therapy and complementary therapies.

At The Health Lodge, our goals in treating Blastocystosis include eradicating the Blastocystis infection, correcting nutrient deficiencies, identifying and managing food allergies and intolerances, and repairing the gut wall and digestive function. We believe that a multidisciplinary team of health care professionals is essential in managing all the aspects of health. Depending on your individual needs, your multidisciplinary team may include general practitioners, psychologists, dietitians or nutritionists, naturopaths, osteopaths, and acupuncturists. This comprehensive and holistic approach is designed to support your physical, mental, and emotional wellbeing.