Blastocystis sp.: A Hidden Player in Gut Health and Disease

Abstract

Blastocystis sp. (Blastocystis) is a prevalent and diverse gastrointestinal parasite, found in up to 60% of humans and animals worldwide, with particularly high rates in immunocompromised individuals and those in close contact with animals. Its extensive genetic diversity presents a major challenge to diagnostic and treatment standardization, making subtype characterization essential for identifying transmission pathways and assessing infection risks. The clinical significance of Blastocystis is increasingly evident, as it is implicated in a range of gastrointestinal conditions, including irritable bowel syndrome, inflammatory bowel disease, and chronic diarrhea. Its interactions with the host’s immune system and gut microbiome add layers of complexity, shaping the parasite’s impact on health and disease in unpredictable ways. This review examines the multifaceted role of Blastocystis in human health, exploring its association with gastrointestinal disorders, cancer, and dysbiosis, while also evaluating current treatment options and emerging therapeutic strategies. A deeper understanding of these interactions could unlock more effective, targeted interventions for managing Blastocystis infections and the conditions they may influence.

Graphical abstract. Clinical significance and management of Blastocystis infection: Blastocystis is associated with cancer, inflammatory bowel disease, and gut microbiota dysbiosis. Current challenges include drug resistance and adverse effects of medications. Standard treatments involve antibiotics and antimicrobials, while alternative approaches such as probiotics, fecal microbiota transplantation, and nanotechnology-assisted drug delivery are being explored.