INTRODUCTION: Decreasing biotic diversity with increasing latitude is an almost universal macroecological pattern documented for a broad range of taxa, however, there have been few studies focused on changes in gut microbiota (GM) across climatic zones. METHODS: Using 16S rRNA amplicon profiling, we analyzed GM variation between temperate (Czechia) and tropical (Cameroon) populations of 99 passerine bird species and assessed GM similarity of temperate species migrating to tropical regions with that of residents/short-distance migrants and tropical residents. Our study also considered the possible influence of diet on GM. RESULTS: We observed no consistent GM diversity differences between tropical and temperate species. In the tropics, GM composition varied substantially between dry and rainy seasons and only a few taxa exhibited consistent differential abundance between tropical and temperate zones, irrespective of migration behavior and seasonal GM changes. During the breeding season, trans-Saharan migrant GM diverged little from species not overwintering in the tropics and did not show higher similarity to tropical passerines than temperate residents/short-distance migrants. Interestingly, GM of two temperate-breeding trans-Saharan migrants sampled in the tropical zone matched that of tropical residents and converged with other temperate species during the breeding season. Diet had a slight effect on GM composition of tropical species, but no effect on GM of temperate hosts. DISCUSSION: Consequently, our results demonstrate extensive passerine GM plasticity, the dominant role of environmental factors in its composition and limited effect of diet.

• Klíčová slova
• climatic zones, faecal microbiome, gastrointestinal tract, metabarcoding, passerine birds,
• Publikační typ
• časopisecké články MeSH

According to the hygiene and biodiversity hypotheses, increased hygiene levels and reduced contact with biodiversity can partially explain the high prevalence of immune-mediated diseases in developed countries. A disturbed commensal microbiota, especially in the gut, has been linked to multiple immune-mediated diseases. Previous studies imply that gut microbiota composition is associated with the everyday living environment and can be modified by increasing direct physical exposure to biodiverse materials. In this pilot study, the effects of rural-second-home tourism were investigated on the gut microbiota for the first time. Rural-second-home tourism, a popular form of outdoor recreation in Northern Europe, North America, and Russia, has the potential to alter the human microbiota by increasing exposure to nature and environmental microbes. The hypotheses were that the use of rural second homes is associated with differences in the gut microbiota and that the microbiota related to health benefits are more diverse or common among the rural-second-home users. Based on 16S rRNA Illumina MiSeq sequencing of stool samples from 10 urban elderly having access and 15 lacking access to a rural second home, the first hypothesis was supported: the use of rural second homes was found to be associated with lower gut microbiota diversity and RIG-I-like receptor signaling pathway levels. The second hypothesis was not supported: health-related microbiota were not more diverse or common among the second-home users. The current study encourages further research on the possible health outcomes or causes of the observed microbiological differences. Activities and diet during second-home visits, standard of equipment, surrounding environment, and length of the visits are all postulated to play a role in determining the effects of rural-second-home tourism on the gut microbiota.

• Klíčová slova
• cottage, elderly, fecal microbiota, gut microbiota, immune-mediated diseases, outdoor recreation, rural areas, second home, stool sample,
• MeSH
• lidé MeSH
• mikrobiota * MeSH
• pilotní projekty MeSH
• RNA ribozomální 16S genetika   MeSH
• senioři MeSH
• Check Tag
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Finsko MeSH
• Rusko MeSH
• Severní Amerika MeSH
• Názvy látek
• RNA ribozomální 16S MeSH

The change in the gut microbiome and microbial metabolites in a patient suffering from severe and enduring anorexia nervosa (AN) and diagnosed with small intestinal bacterial overgrowth syndrome (SIBO) was investigated. Microbial gut dysbiosis is associated with both AN and SIBO, and therefore gut microbiome changes by serial fecal microbiota transplantation (FMT) is a possible therapeutic modality. This study assessed the effects of FMT on gut barrier function, microbiota composition, and the levels of bacterial metabolic products. The patient treatment with FMT led to the improvement of gut barrier function, which was altered prior to FMT. Very low bacterial alpha diversity, a lack of beneficial bacteria, together with a great abundance of fungal species were observed in the patient stool sample before FMT. After FMT, both bacterial species richness and gut microbiome evenness increased in the patient, while the fungal alpha diversity decreased. The total short-chain fatty acids (SCFAs) levels (molecules presenting an important source of energy for epithelial gut cells) gradually increased after FMT. Contrarily, one of the most abundant intestinal neurotransmitters, serotonin, tended to decrease throughout the observation period. Overall, gut microbial dysbiosis improvement after FMT was considered. However, there were no signs of patient clinical improvement. The need for an in-depth analysis of the donor´s stool and correct selection pre-FMT is evident.

• Klíčová slova
• Akkermansia, Firmicutes/Bacteroides, fecal microbiota transplantation (FMT), microbial metabolites, microbiome, short-chain fatty acids, small intestinal bacterial overgrowth syndrome,
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

The gastrointestinal tract of vertebrates is inhabited by diverse bacterial communities that induce marked effects on the host physiology and health status. The composition of the gastrointestinal microbiota is characterized by pronounced taxonomic and functional variability among different regions of the vertebrate gastrointestinal tract. Despite the relatively solid knowledge on the among-region variations of the gastrointestinal microbiota in model mammalian species, there are only a few studies concerning among-region variations of the gastrointestinal microbiota in free-living non-mammalian vertebrate taxa. We used Illumina MiSeq sequencing of bacterial 16S rRNA amplicons to compare the diversity as well as taxonomic composition of bacterial communities in proximal vs. distal parts of the gastrointestinal tract (represented by oral swabs and faecal samples, respectively) in a wild passerine bird, the great tit (Parus major). The diversity of the oral microbiota was significantly higher compared to the faecal microbiota, whereas interindividual variation was higher in faecal than in oral samples. We also observed a pronounced difference in taxonomic content between the oral and faecal microbiota. Bacteria belonging to the phyla Proteobacteria, Firmicutes and Actinobacteria typically dominated in both oral and faecal samples. A high abundance of bacteria belonging to Tenericutes was observed only in faecal samples. Surprisingly, we found only a slight correlation between the faecal and oral microbiota at the within-individual level, suggesting that the microbial composition in these body sites is shaped by independent regulatory processes. Given the independence of these two communities at the individual level, we propose that simultaneous sampling of the faecal and oral microbiota will extend our understanding of host vs. microbiota interactions in wild populations.

• MeSH
• feces mikrobiologie   MeSH
• mikrobiota * MeSH
• Passeriformes mikrobiologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• ústa mikrobiologie   MeSH
• výpočetní biologie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• RNA ribozomální 16S MeSH

The protective effect of Enterococcus faecium EFAL41 on chicken's caecum in relation to the TLR (TLR4 and TLR21) activation and production of luminal IgA challenged with Campylobacter jejuni CCM6191 was assessed. The activation of MIF, IFN-β, MD-2 and CD14 was followed-up after bacterial infection. Day-old chicks (40) were divided into four groups (n = 10): control (C), E. faecium AL41 (EFAL41), C. jejuni (CJ) and combined E. faecium AL41+C. jejuni (EFAL41+CJ). Relative mRNA expression of TLR4, TLR21 and CD14 was upregulated in the probiotic strain and infected (combined) group on day 4 and 7 post infection (p.i.). The caecal relative MD-2 mRNA expression was upregulated on day 4 p.i. in the EFAL41+CJ and CJ groups. MIF and IFN-β reached the highest levels in the combined groups on day 7 p.i. The concentration of the sIgA in intestinal flush was upregulated in EFAL41+CJ group on day 4 p.i. The results demonstrated that E. faecium EFAL41 probiotic strain can modulate the TLRs expression and modify the activation of MIF, IFN-β, MD-2 and CD14 molecules in the chickens caecum challenged with C. jejuni CCM 6191. The counts of EFAL41 were sufficient and high, similarly the counts of enterococci in both, caecum and faeces but without reduction of Campylobacter counts.

• MeSH
• antigeny CD14 genetika   imunologie   MeSH
• Campylobacter jejuni růst a vývoj   MeSH
• cékum imunologie   mikrobiologie   MeSH
• Enterococcus faecium růst a vývoj   imunologie   MeSH
• feces mikrobiologie   MeSH
• imunoglobulin A sekreční genetika   MeSH
• interakce hostitele a patogenu MeSH
• interferon beta genetika   imunologie   MeSH
• kampylobakterové infekce dietoterapie   imunologie   mikrobiologie   veterinární   MeSH
• kur domácí MeSH
• lymfocytární antigen 96 genetika   imunologie   MeSH
• nemoci drůbeže dietoterapie   genetika   imunologie   mikrobiologie   MeSH
• novorozená zvířata MeSH
• probiotika farmakologie   MeSH
• protein - isoformy genetika   imunologie   MeSH
• receptory imunologické genetika   imunologie   MeSH
• regulace genové exprese MeSH
• signální transdukce MeSH
• toll-like receptor 4 genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny CD14 MeSH
• imunoglobulin A sekreční MeSH
• interferon beta MeSH
• lymfocytární antigen 96 MeSH
• macrophage migration inhibitory factor receptor MeSH Prohlížeč
• protein - isoformy MeSH
• receptory imunologické MeSH
• toll-like receptor 4 MeSH

Animal bodies are inhabited by a taxonomically and functionally diverse community of symbiotic and commensal microorganisms. From an ecological and evolutionary perspective, inter-individual variation in host-associated microbiota contributes to physiological and immune system variation. As such, host-associated microbiota may be considered an integral part of the host's phenotype, serving as a substrate for natural selection. This assumes that host-associated microbiota exhibits high temporal stability, however, and that its composition is shaped by trans-generational transfer or heritable host-associated microbiota modulators encoded by the host genome. Although this concept is widely accepted, its crucial assumptions have rarely been tested in wild vertebrate populations. We performed 16S rRNA metabarcoding on an extensive set of fecal microbiota (FM) samples from an insectivorous, long-distance migratory bird, the barn swallow (Hirundo rustica). Our data revealed clear differences in FM among juveniles and adults as regards taxonomic and functional composition, diversity and co-occurrence network complexity. Multiple FM samples from the same juvenile or adult collected within single breeding seasons exhibited higher similarity than expected by chance, as did adult FM samples over two consecutive years. Despite low effect sizes for FM stability over time at the community level, we identified an adult FM subset with relative abundances exhibiting significant temporal consistency, possibly inducing long-term effects on the host phenotype. Our data also indicate a slight maternal (but not paternal) effect on FM composition in social offspring, though this is unlikely to persist into adulthood. We discuss our findings in the context of both evolution and ecology of microbiota vs. host interactions and barn swallow biology.

• Klíčová slova
• barn swallow, fecal microbiota, gastrointestinal tract, metagenome, microbiome, symbiosis,
• Publikační typ
• časopisecké články MeSH

HIV-1 infection is associated with an early and profound depletion of mucosal memory CD4+ T cells, a population that plays an indispensable role in the regulation of isotype switching and transepithelial transport of antibodies. In this study, we addressed whether the depletion of CD4+ T cell in HIV-1-infected individuals results in altered humoral responses specific to antigens encountered at mucosal surfaces. Comprehensive protein microarray of systemic humoral responses to intestinal microbiota demonstrated reduced IgG responses to antigens derived from Proteobacteria and Firmicutes but not Bacteroidetes. Importantly, intestinal secretions of antiretroviral therapy-treated HIV-1-infected individuals exhibited a significant elevation of IgM levels and decreased IgA/IgM and IgG/IgM ratios of antibodies specific to a variety of microbial and food antigens. The presented findings indicate reduced competence of mucosal B cells for class switch recombination from IgM to other isotypes limiting their capacity to react to changing antigenic variety in the gut lumen. Decreased availability of microbiota-specific IgA and IgG may be an important factor contributing to the translocation of microbial antigens across the intestinal mucosal barrier and their systemic dissemination that drives chronic inflammation in HIV-1-infected individuals.

• MeSH
• antigeny imunologie   MeSH
• B-lymfocyty imunologie   MeSH
• CD4-pozitivní T-lymfocyty imunologie   MeSH
• chronická nemoc MeSH
• HIV infekce imunologie   virologie   MeSH
• HIV-1 imunologie   MeSH
• humorální imunita MeSH
• imunoglobulin A imunologie   MeSH
• imunoglobulin G imunologie   MeSH
• lidé MeSH
• mikrobiota imunologie   MeSH
• potraviny MeSH
• přesmyk imunoglobulinových tříd MeSH
• regulace genové exprese MeSH
• střevní sliznice imunologie   virologie   MeSH
• zánět MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antigeny MeSH
• imunoglobulin A MeSH
• imunoglobulin G MeSH

Effects of vertebrate-associated microbiota on physiology and health are of significant interest in current biological research. Most previous studies have focused on host-microbiota interactions in captive-bred mammalian models. These interactions and their outcomes are still relatively understudied, however, in wild populations and non-mammalian taxa. Using deep pyrosequencing, we described the cloacal microbiome (CM) composition in free living barn swallows Hirundo rustica, a long-distance migratory passerine bird. Barn swallow CM was dominated by bacteria of the Actinobacteria, Proteobacteria and Firmicutes phyla. Bacteroidetes, which represent an important proportion of the digestive tract microbiome in many vertebrate species, was relatively rare in barn swallow CM (< 5%). CM composition did not differ between males and females. A significant correlation of CM within breeding pair members is consistent with the hypothesis that cloacal contact during within-pair copulation may promote transfer of bacterial assemblages. This effect on CM composition had a relatively low effect size, however, possibly due to the species' high level of sexual promiscuity.

• MeSH
• bakteriální RNA MeSH
• biodiverzita MeSH
• chov MeSH
• kloaka mikrobiologie   MeSH
• metagenom MeSH
• migrace zvířat * MeSH
• mikrobiota * MeSH
• ptáci mikrobiologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální RNA MeSH
• RNA ribozomální 16S MeSH

The paper provides a basic review of intestinal microflora and its importance in liver diseases. The intestinal microflora has many important functions, above all to maintain the microbial barrier against established as well as potential pathogens. Furthermore, it influences the motility and perfusion of the intestinal wall, stimulates the intestinal immune system and therefore also the so-called common mucosal immune system, reducing bacterial translocation and producing vitamins. Immune homeostasis at mucosal level results from a controlled response to intestinal luminal antigens. In liver cirrhosis, there are many changes in its function, mostly an increase in bacterial overgrowth and translocation. In this review, probiotics and their indications in hepatology are generally discussed. According to recent knowledge, these preparations are indicated in clinical practice only for cases of hepatic encephalopathy. Probiotics are able to decrease the permeability of the intestinal wall, and decrease bacterial translocation and endotoxemia in animal models as well as in clinical studies, which is extremely important in the prevention of complications of liver cirrhosis and infection after liver transplantation. Probiotics could limit oxidative and inflammatory liver damage and, in some situations, improve the histological state, and thus non-alcoholic steatohepatitis could be considered as another possible indication.

• Klíčová slova
• Intestinal microflora, Liver cirrhosis, Liver encephalopathy, Non-alcoholic steatohepatitis, Probiotics,
• MeSH
• gastroenterologie metody   MeSH
• gastrointestinální trakt imunologie   mikrobiologie   MeSH
• lidé MeSH
• nemoci jater farmakoterapie   imunologie   mikrobiologie   MeSH
• probiotika terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH