Blastocystis Hominis

Blastocystis Hominis

Blastocystis hominis is the most prevalent parasite but often isn’t detected due to poor laboratory techniques.

Smart Nutrition’s lab partner detects Blastocystis in more than 20% of clinical specimens.

The weight of evidence supports treating it as a potential pathogen. Together with other weak pathogens, it is associated with many chronic conditions, including irritable bowel, chronic fatigue and arthritic/rheumatoid complaints. Three forms have been identified, and the vacuolated form is most commonly seen in faecal specimens.


  • gastrointestinal cramps
  • nausea and vomiting
  • sleeplessness
  • weight loss
  • lassitude
  • dizziness
  • flatus
  • anorexia
  • pruritus


Blastocystis hominis is often found in patients with classic symptoms of irritable bowel syndrome.


Treatment with metronidazole has been found to eradicate the organism. Blastocystis hominis may be highly variable in its pathogenicity.

The organism is present in a number of healthy individuals, and an asymptomatic carrier state has been postulated. In many patients with gastrointestinal illness, this organism is the only identifiable parasite, and these patients improve when Blastocystis is eradicated.

We find its presence highly correlates with gastrointestinal symptoms; and, along with others, suggest it may be a pathogen in symptomatic patients.

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Please do not return samples to the laboratories that may arrive after Wednesday 27th March and up to and including Monday 2nd April.

The laboratories are closed from the 28th March – 2nd April for the Easter Holiday.