Biology subjects

Boulund, F.

Publications and source records attributed to Boulund, F..

5 recordsLinked to original sources

bioRxiv2024

Profiling the intestinal microbiota, plasma bile acids and inflammation markers reveals novel associations in Crohn's disease and Ulcerative colitis.

Background and aimsOur study explores signatures for Crohns disease (CD) and Ulcerative Colitis (UC) reflecting the interplay between the intestinal microbiota, systemic inflammation, and plasma bile acid homeostasis. Methods1,257 individuals scheduled for colonoscopy were included and completed a comprehensive questionnaire. Individuals with IBD ( CD n=64 and UC n= 55), were age- and gender-matched to controls without findings during colonoscopy. Taxonomic profiles of the fecal microbiota and plasma profiles of inflammatory proteins and bile acids were used to build disease classifiers. Omics integration identified associations across datasets. ResultsB. hydrogenotrophica was associated with CD and C. eutactus, C. sp. CAG 167, B. cellulosilyticus, C. mitsuokai with controls. Ten inflammation markers were increased in CD, and eleven bile acids and derivatives were decreased in CD, while 7a-Hydroxy-3-oxo-4-cholestenoate (7-HOCA) and chenodeoxycholic acid (CDCA) were increased compared to controls. In UC, commensals such as F. prausnitzii and A. muciniphila were depleted. CCL11, IL-17A, and TNF were increased in UC and associated to gut microbial changes. Correlations between taxa and bile acids were all positive. ConclusionsFor both CD and UC, taxonomic differences were primarily characterized by a reduction in commensal gut microbes which exhibited positive correlations with secondary bile acids and negative correlations with inflammation markers, potentially reflecting protective mechanisms of these commensal microbes.

bioinformatics↗

bioRxiv2021

A comparison of approaches to scaffolding multiple regions along the 16S rRNA gene for improved resolution

MotivationFull length, high resolution 16s rRNA marker gene sequencing has been challenging historically. Short amplicons provide high accuracy reads with widely available equipment, at the cost of taxonomic resolution. One recent proposal has been to reconstruct multiple amplicons along the full-length marker gene, however no barcode-free computationally tractable approach for this is available. To address this gap, we present Sidle (SMURF Implementation Done to acceLerate Efficiency), an implementation of the Short MUltiple Reads Framework algorithm with a novel tree building approach to reconstruct rRNA genes from individually amplified regions. ResultsUsing simulated and real data, we compared Sidle to two other approaches of leveraging multiple gene region data. We found that Sidle had the least bias in non-phylogenetic alpha diversity, feature-based measures of beta diversity, and the reconstruction of individual clades. With a curated database, Sidle also provided the most precise species-level resolution. Availability and ImplementationSidle is available under a BSD 3 license from https://github.com/jwdebelius/q2-sidle

bioinformatics↗

bioRxiv2020

Multiomics and digital monitoring during lifestyle changes reveal independent dimensions of human biology and health

In order to explore opportunities for personalized and predictive health care, we collected serial clinical measurements, health surveys and multiomics profiles (genomics, proteomics, autoantibodies, metabolomics and gut microbiome) from 96 individuals. The participants underwent data-driven health coaching over a 16-month period with continuous digital monitoring of activity and sleep. Multiomics factor analysis resulted in an unsupervised, data-driven and integrated view of human health, revealing distinct and independent molecular factors linked to obesity, diabetes, liver function, cardiovascular disease, inflammation, immunity, exercise, diet and hormonal effects. The data revealed novel and previously uncovered associations between risk factors, molecular pathways, and quantitative lifestyle parameters. For example, ethinyl estradiol use had a distinct impact on metabolites, proteins and physiology. Multidimensional molecular and digital health signatures uncovered biological variability between people and quantitative effects of lifestyle changes, hence illustrating the value of the combined use of molecular and digital monitoring of human health.

systems biology↗

bioRxiv2020

Optimal protocols for sequence-based characterization of the human vaginal microbiome

The vaginal microbiome has been connected to a wide range of health outcomes. This has led to a thriving research environment, but also to the use of conflicting methodologies to study its microbial composition. Here we systematically assess best practices for the sequencing-based characterization of the human vaginal microbiome. As far as 16S rRNA gene sequencing is concerned, the V1-V3 region has the best theoretical properties, but limitations of current sequencing technologies mean that the V3-V4 region performs equally well. Both of these approaches present very good agreement with qPCR quantification of key taxa, provided an appropriate bioinformatic pipeline is used. Shotgun metagenomic sequencing presents an interesting alternative to 16S amplification and sequencing, but it is not without its challenges. We have assessed different tools for the removal of host reads and the taxonomic annotation of metagenomic reads, including a new, easy-to-build and - use, reference database of vaginal taxa. This strategy performed as well as the best performing previously published strategies. Despite the many advantages of shotgun sequencing none of the shotgun approaches assessed here had as good agreement with the qPCR data as 16S rRNA gene sequencing. ImportanceThe vaginal microbiome has been connected to a wide range of health outcomes, from susceptibility to sexually transmitted infections to gynecological cancers and pregnancy outcomes. This has led to a thriving research environment, but also to conflicting available methodologies, including many studies that do not report their molecular biological and bioinformatic methods in sufficient detail for them to be considered reproducible. This can lead to conflicting messages and delay progress from descriptive to intervention studies. By systematically assessing best practices for the characterization of the human vaginal microbiome, this study will enable past studies to be assessed more critically and assist future studies in the selection of appropriate methods for their specific research questions.

molecular biology↗

bioRxiv2019

The Prevotella copri complex comprises four distinct clades that are underrepresented in Westernised populations

Prevotella copri is a common inhabitant of the human gut. Interest in P. copri has gathered pace due to conflicting reports on whether it is beneficial or detrimental to health. In a cross-continent meta-analysis exploiting >6,500 available metagenomes supported by new isolate sequencing and recovery of high-quality genomes from metagenomes, we obtained >1,000 P. copri genomes. This 100-fold increase over existing isolate genomes allowed the genetic and global population structure of P. copri to be explored at an unprecedented depth. We demonstrate P. copri is not a monotypic species, but encompasses four distinct clades (>10% inter-clade vs. <4% intra-clade average single nucleotide variants) for which we propose the name P. copri complex, comprising clades A, B, C and D. We show the complex is near ubiquitous in non-Westernised populations (95.4% versus 29.6% in Westernised populations), where all four clades are typically co-present within an individual (61.6% of the cases), in contrast to Westernised populations (4.6%). Genomic analysis of the complex reveals substantial and complementary functional diversity, including the potential for utilisation of complex carbohydrates, suggestive that multi-generational dietary modifications may be a driver for the reduced P. copri prevalence in Westernised populations. Analysis of ancient stool microbiomes highlights a similar pattern of P. copri presence consistent with modern non-Westernised populations, allowing us to estimate the time of clade delineation to pre-date human migratory waves out of Africa. Our analysis reveals P. copri to be far more diverse than previously appreciated and this diversity appears to be underrepresented in Western-lifestyle populations.

microbiology↗