Blastocystomics

Blastocystis sp. is a eukaryotic gut microorganism with a questionable pathogenicity, which often makes it the subject of debate whether it should be considered a parasite or a commensal. This stramenopile is thought to be carried in the gastrointestinal tract of several billion people worldwide and is associated with symptoms in only a few of these cases. At present, there are at least 46 subtypes (ST) colonizing mammalian hosts within the Blastocystis genus, with others that have been found to colonize a variety of other vertebrates and invertebrates. It is via this subtyping system that mammalian isolates are named, rather than the standard binomial nomenclature of a genus and species name. Most of the genomes of these 46 subtypes are yet to be characterized, with only ST1�ST4 and ST6�ST9 were annotated, or draft genomes assembled. Metabolomics, on the other hand, can be used to identify the metabolites produced by Blastocystis, which can be applied as a tool to understand the processes that this microbe is undertaking under certain conditions. Another area of interest is the associations of Blastocystis with other inhabitants of the gut microbiome, and how it could be affecting the composition of these populations. Generally, it is found that Blastocystis occurs alongside a high diversity of other gut microbiota, although some studies disagree, saying it could be correlated to dysbiotic conditions such as those associated with irritable bowel syndrome (IBS). In this chapter, we evaluate the current status quo on the different omics techniques currently used to characterize Blastocystis biology and suggest further avenues to be explored in the future. These will help us better understand its elusive role in the ecosystem that is the gut of humans and other animals.