Blastocystis hominis: A long-term ignored intestinal parasite

Blastocystis hominis is a protozoan parasite inhabiting in the intestinal tract of human. A number of studies showed it is often the most frequent protozoan reported in human fecal samples from both symptomatic patients and asymptomatic carriers. This organism was in the first time reported as a harmless yeast, and has been neglected for a long time. The life cycle, mode of transmission, cell biology and pathogenesis of B. hominis are still not well understood. In recent years, numerous reports have suggested that B. hominis is associated with diarrhea and is considered as a potential pathogen in human. However, the pathogenicity of B. hominis is still a controversial issue, and it has attracted the attention of researchers to initiate studies on the biology, epidemiology and clinical aspects of this parasite. This article described the taxonomy, morphology, life cycle, and epidemiology of B. hominis.