An organism-wide ATAC-seq peak catalog for the bovine and its use to identify regulatory variants.

We report the generation of an organism-wide catalog of 976,813 cis-acting regulatory elements for the bovine detected by the assay for transposase accessible chromatin using sequencing (ATAC-seq). We regroup these regulatory elements in 16 components by nonnegative matrix factorization. Correlation between the genome-wide density of peaks and transcription start sites, correlation between peak accessibility and expression of neighboring genes, and enrichment in transcription factor binding motifs support their regulatory potential. Using a previously established catalog of 12,736,643 variants, we show that the proportion of single-nucleotide polymorphisms mapping to ATAC-seq peaks is higher than expected and that this is owing to an approximately 1.3-fold higher mutation rate within peaks. Their site frequency spectrum indicates that variants in ATAC-seq peaks are subject to purifying selection. We generate eQTL data sets for liver and blood and show that variants that drive eQTL fall into liver- and blood-specific ATAC-seq peaks more often than expected by chance. We combine ATAC-seq and eQTL data to estimate that the proportion of regulatory variants mapping to ATAC-seq peaks is approximately one in three and that the proportion of variants mapping to ATAC-seq peaks that are regulatory is approximately one in 25. We discuss the implication of these findings on the utility of ATAC-seq information to improve the accuracy of genomic selection.

Association Between Human Gut Microbiome and N-Glycan Composition of Total Plasma Proteome.

Being one of the most dynamic entities in the human body, glycosylation of proteins fine-tunes the activity of the organismal machinery, including the immune system, and mediates the interaction with the human microbial consortium, typically represented by the gut microbiome. Using data from 194 healthy individuals, we conducted an associational study to uncover potential relations between the gut microbiome and the blood plasma N-glycome, including N-glycome of immunoglobulin G. While lacking strong linkages on the multivariate level, we were able to identify associations between alpha and beta microbiome diversity and the blood plasma N-glycome profile. Moreover, for two bacterial genera, namely, Bilophila and Clostridium innocuum, significant associations with specific glycans were also shown. The study's results suggest a non-trivial, possibly weak link between the total plasma N-glycome and the gut microbiome, predominantly involving glycans related to the immune system proteins, including immunoglobulin G. Further studies of glycans linked to microbiome-related proteins in well-selected patient groups are required to conclusively establish specific associations.

The impact of Opisthorchis felineus infection and praziquantel treatment on the intestinal microbiota in children.

The presence of some species of helminths is associated with changes in host microbiota composition and diversity, which varies widely depending on the infecting helminth species and other factors. We conducted a prospective case-control study to evaluate the gut microbiota in children with Opisthorchis felineus infection (n=50) before and after anthelmintic treatment and in uninfected children (n=49) in the endemic region. A total of 99 children and adolescents aged between 7 and 18 years were enrolled to the study. Helminth infection was assessed before and at 3 months after treatment with praziquantel. A complex examination for each participant was performed in the study, including an assessment of the clinical symptoms and an intestinal microbiota survey by 16S rRNA gene sequencing of stool samples. There was no change in alpha diversity between O. felineus-infected and control groups. We found significant changes in the abundances of bacterial taxa at different taxonomic levels between the infected and uninfected individuals. Enterobacteriaceae family was more abundant in infected participants compared to uninfected children. On the genus level, O. felineus-infected participants' microbiota showed higher levels of Lachnospira, Escherichia-Shigella, Bacteroides, Eubacterium eligens group, Ruminiclostridium 6, Barnesiella, Oscillibacter, Faecalitalea and Anaerosporobacter and reduction of Blautia, Lachnospiraceae FCS020 and Eubacterium hallii group in comparison with the uninfected individuals. Following praziquantel therapy, there were significant differences in abundances of some microorganisms, including an increase of Faecalibacterium and decrease of Megasphaera, Roseburia. Enterobacteriaceae and Escherichia abundances were decreased up to the control group values. Our results highlight the importance of the host-parasite-microbiota interactions for the community health in the endemic regions.

Colorectal Tumour Mucosa Microbiome Is Enriched in Oral Pathogens and Defines Three Subtypes That Correlate with Markers of Tumour Progression.

Long-term dysbiosis of the gut microbiome has a significant impact on colorectal cancer (CRC) progression and explains part of the observed heterogeneity of the disease. Even though the shifts in gut microbiome in the normal-adenoma-carcinoma sequence were described, the landscape of the microbiome within CRC and its associations with clinical variables remain under-explored. We performed 16S rRNA gene sequencing of paired tumour tissue, adjacent visually normal mucosa and stool swabs of 178 patients with stage 0-IV CRC to describe the tumour microbiome and its association with clinical variables. We identified new genera associated either with CRC tumour mucosa or CRC in general. The tumour mucosa was dominated by genera belonging to oral pathogens. Based on the tumour microbiome, we stratified CRC patients into three subtypes, significantly associated with prognostic factors such as tumour grade, sidedness and TNM staging, BRAF mutation and MSI status. We found that the CRC microbiome is strongly correlated with the grade, location and stage, but these associations are dependent on the microbial environment. Our study opens new research avenues in the microbiome CRC biomarker detection of disease progression while identifying its limitations, suggesting the need for combining several sampling sites (e.g., stool and tumour swabs).

Biliary Microbiota and Bile Acid Composition in Cholelithiasis.

BACKGROUND: A functional interplay between BAs and microbial composition in gut is a well-documented phenomenon. In bile, this phenomenon is far less studied, and with this report, we describe the interactions between the BAs and microbiota in this complex biological matrix. Methodology. Thirty-seven gallstone disease patients of which twenty-one with Opisthorchis felineus infection were enrolled in the study. The bile samples were obtained during laparoscopic cholecystectomy for gallstone disease operative treatment. Common bile acid composition was measured by LC-MS/MS. Gallbladder microbiota were previously analyzed with 16S rRNA gene sequencing on Illumina MiSeq platform. The associations between bile acid composition and microbiota were analyzed. RESULTS: Bile acid signature and Opisthorchis felineus infection status exert influence on beta-diversity of bile microbial community. Direct correlations were found between taurocholic acid, taurochenodeoxycholic acid concentrations, and alpha-diversity of bile microbiota. Taurocholic acid and taurochenodeoxycholic acid both show positive associations with the presence of Chitinophagaceae family, Microbacterium and Lutibacterium genera, and Prevotella intermedia. Also, direct associations were identified for taurocholic acid concentration and the presence of Actinomycetales and Bacteroidales orders, Lautropia genus, Jeotgalicoccus psychrophilus, and Haemophilus parainfluenzae as well as for taurochenodeoxycholic acid and Acetobacteraceae family and Sphingomonas genus. There were no differences in bile acid concentrations between O. felineus-infected and noninfected patients. Conclusions/Significance. Associations between diversity, taxonomic profile of bile microbiota, and bile acid levels were evidenced in patients with cholelithiasis. Increase of taurochenodeoxycholic acid and taurocholic acid concentration correlates with bile microbiota alpha-diversity and appearance of opportunistic pathogens.

Opisthorchis felineus infection, risks, and morbidity in rural Western Siberia, Russian Federation.

BACKGROUND: The liver fluke, Opisthorchis felineus, is widely distributed throughout Europe and large parts of the Russian Federation. In Western Siberia, information about opisthorchiasis is lacking although infection may lead to severe liver and bile duct diseases. We aimed to assess the current prevalence of O. felineus infection along with associated risk factors and morbidity in rural Western Siberia. METHODS: We conducted a community-based, cross-sectional study in the rural Shegarskiy district, Tomsk Oblast, Russian Federation. All household members (≥ 7 years) present on the survey day were enrolled (n = 600). Two stool samples per person were examined for helminth eggs, using PARASEP (DiaSys Ltd, UK). The number of eggs per gram (EPG) of feces was recorded. Each study participant was interviewed to determine risk factors, using a pre-tested questionnaire. An abdominal ultrasonography examination of liver and bile ducts was performed with a mobile, high resolution ultrasound device. In total, 488 persons completed assessments (two stool samples, completed questionnaires); of those, 436 individuals had an ultrasonography (US) examination. RESULTS: We observed a prevalence of O. felineus infection of 60.2%. Significant risk factors for infection were the consumption of river fish (odds ratio from adjusted analysis [aOR] 2.4, 95% CI 1.52-3.95, p<0.001), particularly stock fish (OR from multivariable analysis [mOR] 3.2, 95% CI 2.63-3.80, p<0.001), smoked fish (mOR 1.5, 95% CI 1.24-1.72, p<0.001), frozen fish (mOR 1.6, 95% CI 1.29-2.02, p<0.001), and raw fish (mOR 1.4, 95% CI 1.05-1.84, p = 0.02); and fishing activities (mOR 1.2, 95% CI 1.03-1.43, p = 0.019). Women had a higher risk of infection than men. Infection was associated positively with age and negatively with socio-economic status. The respondents' general awareness of opisthorchiasis was quite high (93.2%), but their knowledge about infection transmission and prevention was insufficient. Children aged 7-18 years old had a lower level of awareness compared to adults. The abdominal ultrasonography results demonstrated a strong association between O. felineus infection and gallbladder stones (mOR 2.8, 95% CI 1.33-6.04, p = 0.007) and periductal fibrosis of intrahepatic bile ducts (mOR 1.9, 95% CI 1.08-3.46, p = 0.026). CONCLUSION: O. felineus infection is highly prevalent in rural regions of Western Siberia, and associated with severe hepatobiliary pathology. Identified risk factors will be used to develop a comprehensive targeted O. felineus infection control program.

Opisthorchiasis and the Microbiome.

The liver flukes Opisthorchis viverrini, O. felineus, and Clonorchis sinensis are closely related fish-borne trematodes endemic in East Asia, Eurasia, and Siberia. Following ingestion, the parasites locate to the biliary tree, where chronic infection frequently leads to cholangiocarcinoma (CCA). Infection with C. sinensis or O. viverrini is classified as a Group 1 carcinogen by the International Agency for Research on Cancer. Infection with O. felineus may also be carcinogenic. The mechanism(s) by which infection with these liver flukes culminates in CCA remain elusive, although they are likely to be multi-factorial. Not yet well studied is the influence of opisthorchiasis on the microbiome of the host despite reports that helminth parasites are capable of affecting the microbiome, potentially modulating gastrointestinal inflammation in response to the appearance of pathogenic strains of bacteria. Here, we review recent findings related to opisthorchiasis and the microbiome and related issues. In the hamster, a tractable model of infection with liver fluke and of infection-induced biliary morbidity and CCA, infection with O. viverrini perturbs the microbiome of the gastrointestinal tract, including increasing numbers of Lachnospiraceae, Ruminococcaceae, Lactobacillaceae, and others, while decreasing Porphyromonadaceae, Erysipelotrichaceae, and Eubacteriaceae. In addition, a complex microbial community associates with the parasites within the biliary tree, including Helicobacter pylori and related bacteria. Moreover, higher rates of infection with Helicobacter occur in Thailand in persons with opisthorchiasis in a liver fluke infection intensity-dependent manner. Experimental infection of hamsters with Opisthorchis felineus results in increased alpha diversity of the microbiota diversity in the biliary tract. In humans, infection with O. felineus modifies the composition of the biliary microbiome, with increasing numbers of species of Klebsiella, Aggregatibacter, Lactobacillus, Treponema, and others. Several phylotypes of Archaea occurred solely in bile from persons infected with O. felineus.