Blastocystis: getting to grips with our guileful guest

• Can Blastocystis induce or contribute to dysbiosis? Or could Blastocystis serve as a biomarker of microbiota homeostasis including high intestinal microbial diversity?
• Do different microbiota favor establishment of different subtypes? Or what determines the relative success of establishment of each ST in different hosts?
• What genes are involved in regulating transition from one morphotype to another?
• How can different sub- and genotypes be characterized in terms of the existence and expression of cysteine proteases and similar virulence proteins?

Blastocystis, a common single-celled intestinal parasite of humans and animals, continues to puzzle clinical microbiologists, gastroenterologists, and general practitioners who are still unsure of the clinical significance of the organism. Here we consider some less well-addressed areas of Blastocystis research, which, facilitated by recent technological advances, could potentially turn out to be significant pathways to knowledge. First and foremost we discuss new trends in Blastocystis research, including the ‘omics’ perspectives, and then highlight some aspects of Blastocystis research in the context of host coevolution, its potential as a biomarker of intestinal functionality, and its relationship to other components of the human intestinal microbiota.