A Study on the Prevalence and Subtype Diversity of the Intestinal Protist Blastocystis sp. in a Gut-Healthy Human Population in the Czech Republic

Abstract

Blastocystis sp. is a common intestinal protist colonizing the human intestine the prevalence of which varies across non-industrialized and industrialized countries. Its role in the human gut ecosystem remains unclear due to persisting gaps in knowledge of epidemiology and factors affecting gut colonization. Here, we aimed to expand the knowledge of the epidemiology of Blastocystis sp. in the gut-healthy humans in one of the industrialized European countries, including the distribution of its subtypes, the correlation between its occurrence and several factors such as lifestyle, contact with animals, age, and sex. A total of 288 stool samples were obtained from asymptomatic individuals over the entire age-range and 136 samples from animals with which the volunteers were in frequent contact. All samples were examined in parallel by PCR and xenic in vitro culture. Blastocystis sp. was detected in samples from both human and non-human hosts. In humans, the overall prevalence was 24% and eight subtypes were found; in animals, the prevalence was 10%, and only five subtypes were detected. A higher incidence of Blastocystis sp. was observed in individuals (i) traveling outside Europe, (ii) in frequent contact with livestock, and (iii) over 50 years of age. We found no effect on gender on Blastocystis sp. colonization. Summary This study provides data on the prevalence and diversity of the gut protist Blastocystis sp. and its subtypes in a gut-healthy human population with emphasis on several factors such as contact with animals, lifestyle, age, and gender.

Blastocystis Colonization Alters the Gut Microbiome and, in Some Cases, Promotes Faster Recovery From Induced Colitis

“…Blastocystis is a common inhabitant of the large intestine of many animals and over a billion people worldwide ( Stensvold and Clark, 2016 ). In developing countries, Blastocystis prevalence in human population can reach 84% ( Poulsen et al, 2016 ) and 100% ( El Safadi et al, 2014 ), and prevalence in industrialized countries ranges between 7 and 50% ( Bart et al, 2013 ; Scanlan et al, 2014 , 2016 ; Seyer et al, 2017 ; Lhotská et al, 2020 ). Yet the role Blastocystis plays in human health and disease is still unclear and the subject of ongoing debate ( Lukeš et al, 2015 ; Chabé et al, 2017 ; Stensvold et al, 2020 ).…”

Use of Oxford Nanopore MinION to generate full-length sequences of the Blastocystis small subunit (SSU) rRNA gene

“…Within the genus Blastocystis , 28 genetic groups named as subtypes (STs) have been proposed, based on polymorphism in the SSU rRNA gene [ 14 , 15 ]. Of the 28 proposed subtypes, 22 subtypes (ST1–ST17, ST21, ST23–ST26) have been acknowledged as legitimate subtypes meeting the criteria of having SSU rDNA sequences that differ by 4% or more [ 14 , 16 ]. These subtypes have been named using a numbering system that is currently sequential and based on publication date.…”

Blastocystis in the faeces of children from six distant countries: prevalence, quantity, subtypes and the relation to the gut bacteriome

“…Several studies should be however pinpointed that performed Blastocystis detection and typing in the presently reported populations. Petrášová et al reported data from six researchers working at a Tanzanian primate forest reserve (all 6 were positive) [ 28 ]; Lhotská et al studied volunteers in Czechia, finding a 24.3% (12/49) positivity in children [ 29 ], not significantly different from the present report; Alfellani et al studied a rather heterogeneous collection of datasets that also included Nigerian patients (adults, with 49% positivity) [ 9 ]. Finally, rural children in Nigeria were studied by Poulsen et al [ 30 ] who reported a prevalence of 84% in the village of Illero in Western Nigeria.…”