Download or read book Evaluating Molecular Methods for Human Microbiome Analysis written by Katherine Margaret Kennedy and published by . This book was released on 2014 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: In human microbiome analysis, sequencing of bacterial 16S rRNA genes has revealed a role for the gut microbiota in maintaining health and contributing to various pathologies. Novel community analysis techniques must be evaluated in terms of bias, sensitivity, and reproducibility and compared to existing techniques to be effectively implemented. Next-generation sequencing technologies offer many advantages over traditional fingerprinting methods, but this extensive evaluation required for the most efficacious use of data has not been performed previously. Illumina libraries were generated from the V3 region of the 16S rRNA gene of samples taken from 12 unique sites within the gastrointestinal tract for each of 4 individuals. Fingerprint data were generated from these samples and prominent bands were sequenced. Sequenced bands were matched with OTUs within their respective libraries. The results demonstrate that denaturing gradient gel electrophoresis (DGGE) represents relatively abundant bacterial taxa (>0.1%). The [beta]-diversity of all samples was compared using Principal Coordinates Analysis (PCoA) of UniFrac distances and Multi-Response Permutation Procedure (MRPP) was applied to measure sample cluster strength and significance; indicator species analysis of fingerprint bands and Illumina OTUs were also compared. The results demonstrate overall similarities between community profiling methods but also indicate that sequence data were not subject to the same limitations observed with the DGGE method (i.e., only abundant taxa bands are resolved, unable to distinguish disparate samples). In addition, the effect of stochastic fluctuations in PCR efficiency ("PCR drift") has not been rigorously tested and may differ for DGGE and next-generation sequencing. I compared pooled and individual reactions for samples of high and low template concentration for both Illumina and DGGE using the combined V3-V4 region of the 16S rRNA gene, and demonstrated that template concentration has a greater impact on reproducibility than pooling. This research shows congruity between two disparate molecular methods, identifies sources of bias, and establishes new guidelines for minimizing bias in microbial community analyses.
Download or read book Molecular Methods for Evaluating the Human Microbiome written by Katherine Margaret Kennedy and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbiomes of the Built Environment written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-10-06 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: People's desire to understand the environments in which they live is a natural one. People spend most of their time in spaces and structures designed, built, and managed by humans, and it is estimated that people in developed countries now spend 90 percent of their lives indoors. As people move from homes to workplaces, traveling in cars and on transit systems, microorganisms are continually with and around them. The human-associated microbes that are shed, along with the human behaviors that affect their transport and removal, make significant contributions to the diversity of the indoor microbiome. The characteristics of "healthy" indoor environments cannot yet be defined, nor do microbial, clinical, and building researchers yet understand how to modify features of indoor environmentsâ€"such as building ventilation systems and the chemistry of building materialsâ€"in ways that would have predictable impacts on microbial communities to promote health and prevent disease. The factors that affect the environments within buildings, the ways in which building characteristics influence the composition and function of indoor microbial communities, and the ways in which these microbial communities relate to human health and well-being are extraordinarily complex and can be explored only as a dynamic, interconnected ecosystem by engaging the fields of microbial biology and ecology, chemistry, building science, and human physiology. This report reviews what is known about the intersection of these disciplines, and how new tools may facilitate advances in understanding the ecosystem of built environments, indoor microbiomes, and effects on human health and well-being. It offers a research agenda to generate the information needed so that stakeholders with an interest in understanding the impacts of built environments will be able to make more informed decisions.
Download or read book Environmental Chemicals the Human Microbiome and Health Risk written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2018-03-01 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: A great number of diverse microorganisms inhabit the human body and are collectively referred to as the human microbiome. Until recently, the role of the human microbiome in maintaining human health was not fully appreciated. Today, however, research is beginning to elucidate associations between perturbations in the human microbiome and human disease and the factors that might be responsible for the perturbations. Studies have indicated that the human microbiome could be affected by environmental chemicals or could modulate exposure to environmental chemicals. Environmental Chemicals, the Human Microbiome, and Health Risk presents a research strategy to improve our understanding of the interactions between environmental chemicals and the human microbiome and the implications of those interactions for human health risk. This report identifies barriers to such research and opportunities for collaboration, highlights key aspects of the human microbiome and its relation to health, describes potential interactions between environmental chemicals and the human microbiome, reviews the risk-assessment framework and reasons for incorporating chemicalâ€"microbiome interactions.
Download or read book Development and Analysis of Molecular Methods for Functional Metagenomics of the Human Gut Microbiome written by Kathy Nguyen Lam and published by . This book was released on 2016 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in the human microbiome has risen quickly in recent years as the microbes that live in and on our body have been implicated in a growing number of human health and disease states. This interest has been supported by advances in DNA sequencing technology that have allowed us to obtain vast amounts of sequence data, and yet we have difficulty assigning function to many of the gene sequences obtained. As research on the role of these microorganisms continues, there will be an increased need for high-throughput methods that can provide knowledge of microbial gene function. Functional metagenomics is one such method, and it relies on first cloning environmental DNA to generate metagenomic libraries that are maintained in Escherichia coli and second, screening the cloned DNA for particular functions of interest. This powerful function-first method allows for the isolation of genes whose role may not have been predicted using DNA sequence homology. This thesis describes the analysis of techniques used in functional metagenomics research, as well as the development of new strategies to aid in functional screening of metagenomic libraries, particularly those constructed from gut-derived DNA. The work is divided into four data chapters that each explore a distinct aspect of the functional metagenomics approach. The first data chapter describes the evaluation of a pooled strategy for sequencing cosmid clones that were previously isolated in functional screens of metagenomic libraries. Ninety-two large-insert clones were pooled for Illumina-sequencing and the assembled sequence data were evaluated against reference sequence data that were obtained from individual barcoded Illumina sequencing of the same clones. The results indicated that a pooled strategy works well provided that sufficient sequencing depth is obtained and that pooled clones do not share sequence similarity to the extent that would be problematic for assembly of short reads that derive from those clones. The second data chapter is an exploration of possible causes for the known cloning bias of metagenomic libraries, by comparing environmental DNA before cloning to the DNA cloned in the final metagenomic library in E. coli. For a human gut metagenomic library, DNA was sampled and Illumina-sequenced at three different steps during the construction of the library. Analyses of the sequence data showed that there was indeed major bias in the final library, but that the bias was not due to fragmentation of the DNA during the cloning process as has been previously suggested; rather, the data were consistent with alternative hypotheses that suggest bias occurs after the DNA is introduced into E. coli, and analyses provide support for the hypothesis that spurious transcription of foreign DNA in E. coli may be contributing to the bias of libraries. Bias was also examined for a soil metagenomic library using 16S rRNA gene sequencing and though broad phylum-level biases were not as severe as observed for the human gut library, analyses revealed a bias in the relative abundance of individual OTUs. The third data chapter describes efforts to develop Bacteroides thetaiotaomicron (B. theta) VPI-5482 as a surrogate host for screening metagenomic libraries constructed from human gut-derived DNA. In this strategy, metagenomic libraries that have been constructed in E. coli can be transferred to B. theta using triparental conjugation. A member of the Bacteroidetes was chosen to specifically address the likely barrier to gene expression in E. coli of DNA that originates from this phylum. To allow the library to be replicated in B. theta, a B. theta-compatible library cloning vector was constructed, and this vector was used to generate genomic and metagenomic clone libraries. A metagenomic library was successfully screened in B. theta, leading to functional complementation of a B. theta mutant strain unable to grow on chondroitin sulfate as sole carbon source. However, further examination of the complemented clones indicated that the library clone DNA had integrated into the B. theta mutant genome. To address this problem, an alternative method for screening was devised, and although this method demonstrates that screening in B. theta remains feasible, more work is required to optimize the conjugation efficiency and the level of throughput. The fourth and last data chapter is an exploration of the use of transcriptional terminator elements in library cloning vectors, inspired by the results of previous chapters. Two unidirectional transcriptional terminators were added to a copy number-inducible fosmid vector, flanking the cloning site, with the intention of reducing insert-born transcription into the vector backbone. The terminators were tested using a reporter gene to confirm their functionality in this context, and derivative vectors were generated for future testing of whether or in what contexts terminators may help alleviate cloning bias in metagenomic libraries. The work described in this thesis contributes to method advancement for functional metagenomics through the analysis of a cost-effective strategy for sequencing library clones, the examination of potential causes of sequence bias in metagenomic libraries, the development of a surrogate host for more productive functional screening, and the consideration of vector elements that may improve metagenomic library stability in E. coli.
Download or read book The Human Microbiome Diet and Health written by Food Forum and published by National Academies Press. This book was released on 2013-02-27 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Food Forum convened a public workshop on February 22-23, 2012, to explore current and emerging knowledge of the human microbiome, its role in human health, its interaction with the diet, and the translation of new research findings into tools and products that improve the nutritional quality of the food supply. The Human Microbiome, Diet, and Health: Workshop Summary summarizes the presentations and discussions that took place during the workshop. Over the two day workshop, several themes covered included: The microbiome is integral to human physiology, health, and disease. The microbiome is arguably the most intimate connection that humans have with their external environment, mostly through diet. Given the emerging nature of research on the microbiome, some important methodology issues might still have to be resolved with respect to undersampling and a lack of causal and mechanistic studies. Dietary interventions intended to have an impact on host biology via their impact on the microbiome are being developed, and the market for these products is seeing tremendous success. However, the current regulatory framework poses challenges to industry interest and investment.
Download or read book Microbiome Analysis written by Robert G. Beiko and published by . This book was released on 2018 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Human Microbiome written by Mohsin Khurshid and published by Springer Nature. This book was released on with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Chemistry of Microbiomes written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-07-19 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 21st century has witnessed a complete revolution in the understanding and description of bacteria in eco- systems and microbial assemblages, and how they are regulated by complex interactions among microbes, hosts, and environments. The human organism is no longer considered a monolithic assembly of tissues, but is instead a true ecosystem composed of human cells, bacteria, fungi, algae, and viruses. As such, humans are not unlike other complex ecosystems containing microbial assemblages observed in the marine and earth environments. They all share a basic functional principle: Chemical communication is the universal language that allows such groups to properly function together. These chemical networks regulate interactions like metabolic exchange, antibiosis and symbiosis, and communication. The National Academies of Sciences, Engineering, and Medicine's Chemical Sciences Roundtable organized a series of four seminars in the autumn of 2016 to explore the current advances, opportunities, and challenges toward unveiling this "chemical dark matter" and its role in the regulation and function of different ecosystems. The first three focused on specific ecosystemsâ€"earth, marine, and humanâ€"and the last on all microbiome systems. This publication summarizes the presentations and discussions from the seminars.
Download or read book The Human Microbiome written by and published by Academic Press. This book was released on 2017-11-17 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods in Microbiology, Volume 44 presents the latest volume in the most prestigious series devoted to techniques and methodology in the field, with updated chapters that cover Metabolomics and the vaginal microbial ecosystem and health, Esophageal microbiome, Bioinformatics methods, Evolution of biomolecules, genomes and communities, and Gut microbial metabolism or the acquisition of the gut microbiome. Established for over 30 years, this comprehensive series provides ready-to-use recipes, the latest emerging techniques, and novel approaches on tried, tested and established methods. Written by recognized leaders and experts in the field Provides a comprehensive and cutting-edge review of current and emerging technologies in the field of clinical microbiology Presents discussions on newly emerging technologies
Download or read book Evaluating Methods for the Optimal Extraction of Microbial Nucleic Acids for Analysis of the Human Gut Microbiota written by Brett C. B. Wagner and published by . This book was released on 2014 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metagenomics of the Human Body written by Karen E. Nelson and published by Springer Science & Business Media. This book was released on 2010-11-16 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book brings a completely different perspective than available books by combining the information gained from the human genome with that derived from parallel metagenomic studies, and new results from investigating the effects of these microbes on the host immune system. Although there are a number of books that focus on the human genome that are currently available, there are no books that bring to the forefront the mix of the human genome and the genomes and metagenomes of the microbial species that live within and on us.
Download or read book Statistical Analysis of Microbiome Data written by Somnath Datta and published by Springer Nature. This book was released on 2021-10-27 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbiome research has focused on microorganisms that live within the human body and their effects on health. During the last few years, the quantification of microbiome composition in different environments has been facilitated by the advent of high throughput sequencing technologies. The statistical challenges include computational difficulties due to the high volume of data; normalization and quantification of metabolic abundances, relative taxa and bacterial genes; high-dimensionality; multivariate analysis; the inherently compositional nature of the data; and the proper utilization of complementary phylogenetic information. This has resulted in an explosion of statistical approaches aimed at tackling the unique opportunities and challenges presented by microbiome data. This book provides a comprehensive overview of the state of the art in statistical and informatics technologies for microbiome research. In addition to reviewing demonstrably successful cutting-edge methods, particular emphasis is placed on examples in R that rely on available statistical packages for microbiome data. With its wide-ranging approach, the book benefits not only trained statisticians in academia and industry involved in microbiome research, but also other scientists working in microbiomics and in related fields.
Download or read book The Gut Microbiome in Health and Disease written by Dirk Haller and published by Springer. This book was released on 2018-07-27 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides an overview on how the gut microbiome contributes to human health. The readers will get profound knowledge on the connection between intestinal microbiota and immune defense systems. The tools of choice to study the ecology of these highly-specialized microorganism communities such as high-throughput sequencing and metagenomic mining will be presented. In addition the most common diseases associated to the composition of the gut flora are discussed in detail. The book will address researchers, clinicians and advanced students working in biomedicine, microbiology and immunology.
Download or read book Novel Approaches in Microbiome Analyses and Data Visualization written by Jessica Galloway-Peña and published by Frontiers Media SA. This book was released on 2019-02-06 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-throughput sequencing technologies are widely used to study microbial ecology across species and habitats in order to understand the impacts of microbial communities on host health, metabolism, and the environment. Due to the dynamic nature of microbial communities, longitudinal microbiome analyses play an essential role in these types of investigations. Key questions in microbiome studies aim at identifying specific microbial taxa, enterotypes, genes, or metabolites associated with specific outcomes, as well as potential factors that influence microbial communities. However, the characteristics of microbiome data, such as sparsity and skewedness, combined with the nature of data collection, reflected often as uneven sampling or missing data, make commonly employed statistical approaches to handle repeated measures in longitudinal studies inadequate. Therefore, many researchers have begun to investigate methods that could improve incorporating these features when studying clinical, host, metabolic, or environmental associations with longitudinal microbiome data. In addition to the inferential aspect, it is also becoming apparent that visualization of high dimensional data in a way which is both intelligible and comprehensive is another difficult challenge that microbiome researchers face. Visualization is crucial in both the analysis and understanding of metagenomic data. Researchers must create clear graphic representations that give biological insight without being overly complicated. Thus, this Research Topic seeks to both review and provide novels approaches that are being developed to integrate microbiome data and complex metadata into meaningful mathematical, statistical and computational models. We believe this topic is fundamental to understanding the importance of microbial communities and provides a useful reference for other investigators approaching the field.
Download or read book The Human Microbiota written by David N. Fredricks and published by John Wiley & Sons. This book was released on 2013-02-22 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Human Microbiota offers a comprehensive review of all human-associated microbial niches in a single volume, focusing on what modern tools in molecular microbiology are revealing about human microbiota, and how specific microbial communities can be associated with either beneficial effects or diseases. An excellent resource for microbiologists, physicians, infectious disease specialists, and others in the field, the book describes the latest research findings and evaluates the most innovative research approaches and technologies. Perspectives from pioneers in human microbial ecology are provided throughout.
Download or read book Microbial Forensics written by Bruce Budowle and published by Academic Press. This book was released on 2010-10-27 with total page 753 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial Forensics is a rapidly evolving scientific discipline. In the last decade, and particularly due to the anthrax letter attacks in the United States, microbial forensics has become more formalized and has played an increasingly greater role in crime investigations. This has brought renewed interest, development and application of new technologies, and new rules of forensic and policy engagement. It has many applications ranging from biodefense, criminal investigations, providing intelligence information, making society more secure, and helping protect precious resources, particularly human life. A combination of diverse areas is investigated, including the major disciplines of biology, microbiology, medicine, chemistry, physics, statistics, population genetics, and computer science. Microbial Forensics, Second Edition is fully revised and updated and serves as a complete reference of the discipline. It describes the advances, as well as the challenges and opportunities ahead, and will be integral in applying science to help solve future biocrimes. - A collection of microbiology, virology, toxicology and mycology as it relates to forensics, in one reference - New and expanded content to include statistical analysis of forensic data and legal admissibility and the standards of evidence, to name a few - Includes research information and application of that research to crime scene analysis, which will allow practitioners to understand and apply the knowledge to their practice with ease
