Overview of current research on Blastocystis

Research into Blastocystis hominis (Blastocystis) is a growing area of interest around the world as it’s estimated that over 1 billion people have this parasite in their gastrointestinal tracts.

There are conflicting reports of the health effects of Blastocystis’ presence in the large intestine on the gut and overall health, and a reliable detection/ testing for Blastocystis and other intestinal parasites is of key importance for effective treatment – natural, conventional or a combination of both.

It’s a fact that many people who have this parasite feel healthy and don’t have the associated gut symptoms such as diarrhoea, bloating, cramping or pain; whilst others seem to be adversely affected (including gut and other symptoms such as fatigue, brain fog, joint pain and others).

It’s known that Blastocystis can live in the large intestine for a long time (i.e. months or years) after it was acquired, usually through contaminated water or food.

According to Rune Stensvold, a leading researcher in this area, many species of Blastocystis have been discovered, of which at least 9 have been found in humans so far. Such species are currently termed “subtypes” (STs). For example subtypes ST1, ST2, ST3 and ST4 are common in Europe.

While ST1, ST2, and ST3 appear to have equal prevalence in patients with diarrhoea and healthy individuals, ST4 appears to be epidemiologically linked to diarrhoea and/or chronic conditions such as irritable bowel syndrome (IBS).

Rune Stensvold states that there is no known efficient eradication strategy for Blastocystis using conventional drugs, and that successful eradication of Blastocystis is far from straight forward due to drug resistance, treatment failure, and reinfection.

Although Flagyl (Metronidazole) is often prescribed for Blastocystis infections, there are conflicting reports on its efficacy. Even in combination with other drugs such as Paromomycin, Blastocystis eradication can’t be guaranteed. Read more on this HERE.

In October 2018 the 2nd International Blastocystis Conference took place in Bogota, Colombia. Here are the key conclusions as reported by Rune Stensvold:

  • At present, we can’t totally dismiss pathogenicity of Blastocystis; if existing, it may involve both strain- and host-specific factors.
  • Blastocystis comprises many different organisms with different genetic makeups. There is variation not just between subtypes, but also within subtypes. Therefore it can’t be categorically stated that “Blastocystis is either a commensal (neutral or beneficial) or parasite because different Blastocystis isolates could be commensals or parasites depending on the host, the genetic makeup of the parasite and the microbiota with which they interact”.
  • The diversity of Blastocystis in huma