Blastocystis hominis

Blastocystis hominis is a single-celled eukaryotic organism that inhabits the gastrointestinal tract of humans and various animals. This stramenopile exhibits significant genetic diversity and has become an organism of increasing scientific interest due to its widespread distribution and controversial role in human health. Recent molecular studies have identified numerous subtypes, suggesting a complex evolutionary history and host-parasite relationship. The organism is one of the most common intestinal protists in humans, with infection rates reaching up to 100% in some developing regions. While commonly referred to as Blastocystis hominis in humans, the current taxonomic convention recognizes various species and subtypes within the genus Blastocystis, with at least 17 different subtypes identified through molecular analysis.