[Blastocystis spp.: Advances, controversies and future challenges]

Area of Science:

• Medical Parasitology
• Gastroenterology
• Infectious Diseases

Background:

• Blastocystis spp. is the most frequently identified protozoan in human fecal samples globally.
• Infection rates exceed 20% in developing countries, with zoonotic potential suggested by its presence in multiple hosts.
• The clinical significance and pathogenic mechanisms of Blastocystis spp. in the human gut remain incompletely understood.

Purpose of the Study:

• To review the current understanding of Blastocystis spp. as a human intestinal parasite.
• To explore the potential link between Blastocystis spp. and various gastrointestinal disorders.
• To investigate the influence of genetic diversity on the clinical manifestations of Blastocystis infections.

Main Methods:

• Literature review of clinical reports and epidemiological studies on Blastocystis spp.
• Analysis of existing data on the association between Blastocystis spp. and intestinal diseases.
• Examination of research on the genetic diversity of Blastocystis spp. and its potential impact on pathogenicity.

Main Results:

• Blastocystis spp. is a common finding in human stool, particularly in regions with lower sanitation standards.
• While frequently reported, its etiological role in conditions like diarrhea, inflammatory bowel disease (IBD), and ulcerative colitis is not definitively proven.
• Genetic variability among Blastocystis isolates is recognized as a potential factor influencing the spectrum of clinical symptoms.

Conclusions:

• Blastocystis spp. represents a common, yet enigmatic, human intestinal protozoan.
• Further research is required to elucidate the pathogenicity and definitive clinical relevance of Blastocystis infections.
• The genetic diversity of Blastocystis spp. likely plays a crucial role in the varied clinical presentations observed in infected individuals.