Interactions between Blastocystis subtype ST4 and gut microbiota in vitro

Area of Science:

• Microbiology
• Gastroenterology
• Immunology

Background:

• Blastocystis ST4 is a prevalent gastrointestinal protistan parasite.
• Its association with a healthy gut microbiota is suggested but poorly understood.
• The influence of Blastocystis ST4 on gut microbiota composition and function requires further investigation.

Purpose of the Study:

• To investigate the in vitro interactions between Blastocystis ST4 and key intestinal bacteria.
• To elucidate the mechanisms underlying these interactions, including the role of reactive oxygen species (ROS).
• To assess the impact of Blastocystis ST4 and bacterial co-cultures on intestinal epithelial barrier integrity.

Main Methods:

• In vitro co-culture of Blastocystis ST4 with seven representative intestinal bacteria.
• Flow cytometry to analyze reactive oxygen species (ROS) production.
• Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) for oxidative stress-related gene expression.
• Transepithelial electrical resistance (TEER) and flux assays to evaluate epithelial barrier function.

Main Results:

• Blastocystis ST4 demonstrated a beneficial effect on the growth of most co-cultured intestinal bacteria.
• Significant inhibition of Bacteroides vulgatus growth was observed, linked to high ROS levels and oxidative stress gene upregulation.
• Blastocystis ST4 co-incubation protected the intestinal epithelial barrier from damage induced by B. vulgatus.

Conclusions:

• Blastocystis ST4 exerts beneficial effects on commensal intestinal bacteria in vitro.
• Blastocystis ST4 actively inhibits the growth of the pathogen Bacteroides vulgatus.
• These findings support the hypothesis that Blastocystis ST4 may function as a beneficial commensal organism.