External factors affecting composition of the human gut microbiota have attracted considerable attention in recent years. Among these factors, habitat sharing with other humans and companion animals, especially dogs, is considered crucial together with the presence of intestinal protists. The Czech Republic, known for one of the highest rates of dog ownership in Europe, provides an ideal setting for studying such relationships. Here, we investigated the impact of dog ownership and lifestyle factors (residing in cities versus villages) on the gut microbiota (specifically bacteriome). In addition, we also investigated the influence of the common gut protist Blastocystis sp. on the human gut microbiota. Fecal DNAs from 118 humans and 54 dogs were subject to 16S rRNA gene sequencing using the Illumina MiSeq platform. Greater microbial diversity was observed in humans than in dogs. Owning a dog had no significant effect on the alpha and beta diversity of the human microbiota, although some bacterial genera were enriched in dog owners. In relation to lifestyle, urban dwellers had higher levels of Akkermansia, while people living in villages had a more diverse gut microbiota. The presence of Blastocystis sp. in humans correlated with specific microbial patterns, indicating an important role for this micro-eukaryote in the gut ecosystem. These findings highlight the intricate relationship between specific factors and the gut microbiota composition and emphasize the need for more extensive research in this area.

• Klíčová slova
• Blastocystis sp, Dog ownership, Dogs, Gut microbiota, Humans, Lifestyle,
• Publikační typ
• časopisecké články MeSH

The avoidance of infectious disease by widespread use of 'systems hygiene', defined by hygiene-enhancing technology such as sewage systems, water treatment facilities, and secure food storage containers, has led to a dramatic decrease in symbiotic helminths and protists in high-income human populations. Over a half-century of research has revealed that this 'biota alteration' leads to altered immune function and a propensity for chronic inflammatory diseases, including allergic, autoimmune and neuropsychiatric disorders. A recent Ethiopian study (EClinicalMedicine 39: 101054), validating predictions made by several laboratories, found that symbiotic helminths and protists were associated with a reduced risk of severe COVID-19 (adjusted odds ratio = 0.35; p<0.0001). Thus, it is now apparent that 'biome reconstitution', defined as the artificial re-introduction of benign, symbiotic helminths or protists into the ecosystem of the human body, is important not only for alleviation of chronic immune disease, but likely also for pandemic preparedness.

• Klíčová slova
• Biological sciences, Health sciences, Virology,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Blastocystis is the most commonly found intestinal protist in the world. Accurate detection and differentiation of Blastocystis including its subtypes (arguably species) are essential to understand its epidemiology and role in human health. We compared (i) the sensitivity of conventional PCR (cPCR) and qPCR in a set of 288 DNA samples obtained from stool samples of gut-healthy individuals, and (ii) subtype diversity as detected by next-generation sequencing (NGS) versus Sanger sequencing. Real-time PCR resulted in more positive samples than cPCR, revealing high fecal load of Blastocystis based on the quantification curve in most samples. In subtype detection, NGS was largely in agreement with Sanger sequencing but showed higher sensitivity for mixed subtype colonization within one host. This fact together with use of the combination of qPCR and NGS and obtaining information on the fecal protist load will be beneficial for epidemiological and surveillance studies.

TITLE: Comparaison des approches de diagnostic moléculaire pour la détection et la différenciation du protiste intestinal Blastocystis sp. chez l’homme. ABSTRACT: Blastocystis est le protiste intestinal le plus répandu dans le monde. La détection et la différenciation précises de Blastocystis, y compris ses sous-types (sans doute des espèces), sont essentielles pour comprendre son épidémiologie et son rôle dans la santé humaine. Nous avons comparé (i) la sensibilité de la PCR conventionnelle (cPCR) et de la qPCR dans un ensemble de 288 échantillons d’ADN obtenus à partir d’échantillons de selles d’individus en bonne santé intestinale et (ii) la diversité des sous-types détectée par le séquençage de nouvelle génération (NGS) par rapport au séquençage Sanger. La PCR en temps réel a donné plus d’échantillons positifs que la cPCR, révélant une charge fécale élevée de Blastocystis sur la base de la courbe de quantification dans la plupart des échantillons. Dans la détection des sous-types, le NGS était largement en accord avec le séquençage de Sanger mais a montré une sensibilité plus élevée pour la colonisation de sous-types mixtes au sein d’un hôte. Ce fait, associé à l’utilisation de la combinaison de qPCR et de NGS et à l’obtention d’informations sur la charge fécale de protistes, sera bénéfique pour les études épidémiologiques et de surveillance.

• Klíčová slova
• Blastocystis, Conventional-PCR, NGS, Quantification, Sensitivity, qPCR,
• MeSH
• Blastocystis * genetika   MeSH
• blastocystóza * diagnóza   epidemiologie   MeSH
• feces MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• molekulární patologie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Protists are a normal component of mammalian intestinal ecosystems that live alongside, and interact with, bacterial microbiota. Blastocystis, one of the most common intestinal eukaryotes, is reported as a pathogen that causes inflammation and disease, though health consequences likely vary depending on host health, the gut ecosystem, and genetic diversity. Accumulating evidence suggests that Blastocystis is by and large commensal. Blastocystis is more common in healthy individuals than those with immune mediated diseases such as Inflammatory Bowel Diseases (IBD). Blastocystis presence is also associated with altered composition and higher richness of the bacterial gut microbiota. It is not clear whether Blastocystis directly promotes a healthy gut and microbiome or is more likely to colonize and persist in a healthy gut environment. We test this hypothesis by measuring the effect of Blastocystis ST3 colonization on the health and microbiota in a rat experimental model of intestinal inflammation using the haptenizing agent dinitrobenzene sulfonic acid (DNBS). We experimentally colonized rats with Blastocystis ST3 obtained from a healthy, asymptomatic human donor and then induced colitis after 3 weeks (short term exposure experiment) or after 13 weeks (long term exposure experiment) and compared these colonized rats to a colitis-only control group. Across experiments Blastocystis ST3 colonization alters microbiome composition, but not richness, and induces only mild gut inflammation but no clinical symptoms. Our results showed no effect of short-term exposure to Blastocystis ST3 on gut inflammation following colitis induction. In contrast, long-term Blastocystis exposure appears to promote a faster recovery from colitis. There was a significant reduction in inflammatory markers, pathology 2 days after colitis induction in the colonized group, and clinical scores also improved in this group. Blastocystis colonization resulted in a significant reduction in tumor necrosis factor alpha (TNFα) and IL-1β relative gene expression, while expression of IFNγ and IL17re/17C were elevated. We obtained similar results in a previous pilot study. We further found that bacterial richness rebounded in rats colonized by Blastocystis ST3. These results suggest that Blastocystis sp. may alter the gut ecosystem in a protective manner and promote faster recovery from disturbance.

• Klíčová slova
• Blastocystis, DNBS colitis, gut microbiome, inflammation alleviation, rat model, symbiosis,
• Publikační typ
• časopisecké články MeSH

UNLABELLED: 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.

• Klíčová slova
• Blastocystis, Czech Republic, demography, genetic diversity, prevalence, survey,
• MeSH
• Blastocystis * genetika   MeSH
• blastocystóza * epidemiologie   MeSH
• ekosystém MeSH
• feces MeSH
• lidé MeSH
• prevalence MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Evropa MeSH

In light of the current biodiversity crisis, investigating the human impact on non-human primate gut biology is important to understanding the ecological significance of gut community dynamics across changing habitats and its role in conservation. Using traditional coproscopic parasitological techniques, we compared the gastrointestinal protozoan and metazoan symbiont richness of two primates: the Udzungwa red colobus (Procolobus gordonorum) and the yellow baboon (Papio cynocephalus). These species live sympatrically in both protected and unprotected forests within the Udzungwa Mountains of Tanzania with distinct ecological adaptations and diets. Our results showed that terrestrial and omnivorous yellow baboons had 2 (95% CI 1.47-2.73) and 3.78 (2.62-5.46) times higher gut symbiont richness (both including and excluding rare protozoans) compared to the arboreal and leaf-eating Udzungwa red colobus in unprotected and protected forest, respectively. We also found a consistent depletion of symbiont richness in red colobus living in the unprotected forest fragment compared to the continuous protected forests [the latter having 1.97 times (95% CI 1.33-2.92) higher richness], but not in yellow baboons. Richness reduction was particularly evident in the Udzungwa red colobus monkeys, confirming the pattern we reported previously for gut bacterial communities. This study demonstrates the impact of human activities even on the microbiodiversity of the intestinal tract of this species. Against the background of rapid global change and habitat degradation, and given the health benefits of intact gut communities, the decrease in natural gut symbionts reported here is worrying. Further study of these communities should form an essential part of the conservation framework.

• MeSH
• Amoebida * MeSH
• biodiverzita MeSH
• cizopasní červi * MeSH
• Colobus * MeSH
• dieta MeSH
• druhová specificita MeSH
• ekosystém MeSH
• feces MeSH
• lesy MeSH
• lidské činnosti MeSH
• Papio * MeSH
• střeva * MeSH
• symbióza * MeSH
• Trichostomatida * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Tanzanie MeSH

• MeSH
• Bacteria klasifikace   MeSH
• interakce hostitele a patogenu * MeSH
• lidé MeSH
• mikrobiota * MeSH
• molekulární evoluce * MeSH
• paraziti mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH