The relation between Blastocystis and the intestinal microbiota in Swedish travellers
(English)Manuscript (preprint) (Other academic)
Blastocystis sp. is a unicellular eukaryote that is commonly found in the human intestine. Its ability to cause disease is debated and a subject for ongoing research. Many aspects of Blastocystis are not fully known, including its role in the gut microbiota. In this study, faecal samples from 35 Swedish university students were examined with shotgun metagenomics before and after travel to the Indian peninsula or Central Africa. We aimed at assessing the impact of travel on Blastocystis carriage and seek associations between Blastocystis and the bacterial microbiota. We found a prevalence of Blastocystis of 16/35 (46%) before travel and 15/35 (43%) after travel. The two most commonly found Blastocystis subtypes (STs) were ST3 and ST4, accounting for 65% (20/31) of the samples positive for Blastocystis. No mixed subtype carriage was detected. All ten individuals with a typable ST before and after travel maintained their initial ST. The community composition of the gut bacterial microbiota was not significantly different between Blastocystis-carriers and non-carriers. Interestingly, the presence of Blastocystis was associated with the bacterial genera Sporolactobacillus and Candidatus Carsonella, none of which regarded as normal residents of the human intestinal microbiota, but both could be linked to plants. This finding may imply that carriage of Blastocystis is linked to dietary vegetables. Blastocystis carriage was positively correlated to high bacterial genus richness, and negatively correlated to the Bacteroides enterotype. These correlations were both largely driven by ST4, a subtype most commonly described from Europe and Australia, and were not significant for the globally prevalent ST3. Whether the associations of Blastocystis with the bacterial microbiota as described in this study are resulting from the presence of Blastocystis, or are a prerequisite for colonization with Blastocystis, are interesting questions for further studies.
Blastocystis; subtype; persistence; travel; microbiota; Sporolactobacillus; Candidatus Carsonella; transmission
Infectious Medicine Microbiology in the medical area
Research subject Clinical Bacteriology
IdentifiersURN: urn:nbn:se:umu:diva-132437OAI: oai:DiVA.org:umu-132437DiVA: diva2:1081388