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Updated: Mar 27, 2026
Human Blastocyst Biopsy and Vitrification
Published on: July 26, 2019
Eradication of Blastocystis in humans: Really necessary for all?
Özgür Kurt1, Funda Doğruman Al2, Mehmet Tanyüksel3
1Faculty of Medicine, Department of Medical Microbiology, Acibadem University, Istanbul, Turkey.
Abstract:
Blastocystis (initially named as Blastocystis hominis) has long been known as a protist without any clinical significance. However, there is now a huge pile of case reports where Blastocystis is blamed for the symptoms and the infection described in the patients. Introduction of the presence of as many as 17 Blastocystis subtypes while many infected individuals are non-symptomatic initially brought about the correlation between the subtypes and pathogenicity; however, the outcomes of these trials were not consistent and did not explain its pathogenicity. Today, it is mostly acknowledged that Blastocystis may colonize many individuals but the infection's onset depends on the interaction between the virulence of parasites and host's immune competence. Eradication of Blastocystis is essential in some cases where it is the only infectious agent and patient is suffering from some symptoms. In such cases, metronidazole is the drug of choice but its efficacy is relatively low in some cases. Other agents used include trimethoprim-sulfamethoxazole, paromomycin, and furazolidone. Recent studies on the interactions between human health and the role of gut microbiota introduces new data which may significantly change our point of view against some protists, which we tend to see as "parasites requiring urgent eradication for cure". May the presence or absence of some Blastocystis subtypes necessary for human health, or is the absence or presence of certain Blastocystis subtypes in human gut is associated with certain diseases/infections? The answers of these questions will surely guide us to select patients requiring treatment against Blastocystis infection in future.
Insights
Blastocystis, once considered harmless, is now linked to patient symptoms. Its pathogenicity depends on parasite virulence and host immunity, necessitating targeted eradication strategies for symptomatic infections.
Area of Science:
- Medical Parasitology
- Human Microbiome Research
- Infectious Diseases
Background:
- Blastocystis, formerly Blastocystis hominis, is a protist whose clinical significance is debated.
- Increasing case reports link Blastocystis to patient symptoms, challenging its non-pathogenic status.
- The discovery of numerous Blastocystis subtypes initially suggested a link to pathogenicity, but findings remain inconsistent.
Purpose of the Study:
- To explore the complex relationship between Blastocystis subtypes, host immunity, and clinical manifestations.
- To evaluate the current understanding of Blastocystis pathogenicity and treatment efficacy.
- To investigate the potential role of Blastocystis in human health and disease within the context of the gut microbiome.
Main Methods:
- Review of existing case reports and scientific literature on Blastocystis infections.
- Analysis of studies correlating Blastocystis subtypes with pathogenicity.
- Examination of research on host-parasite interactions and immune responses.
- Consideration of emerging data on the human gut microbiota's influence.
Main Results:
- Blastocystis colonization is common, but symptomatic infection hinges on parasite virulence and host immune status.
- Metronidazole is the primary treatment, but its efficacy is variable.
- The role of specific Blastocystis subtypes in disease causation requires further clarification.
- Gut microbiota research may offer new perspectives on Blastocystis's impact on human health.
Conclusions:
- Blastocystis pathogenicity is multifactorial, involving parasite virulence and host immune competence.
- Treatment decisions for Blastocystis should be individualized based on clinical presentation and host factors.
- Further research is needed to determine if certain Blastocystis subtypes are beneficial or detrimental to human health.
- Understanding Blastocystis's role in the gut microbiome is crucial for future diagnostic and therapeutic strategies.
