Role Of Gut Microbiome Host Metabolic Interactions In Metabolic Diseases

The metabolic phenotype of any complex organism is dependent on a complex series of host and gut microbial gene (microbiome) interactions with diet. The microbiome itself can be affected by environmental factors such as stress, exposure to xenobiotics, lifestyle, and alterations in the mammalian-microbial-metabolic axis are associated with changes in disease factors. To understand further the impact of the commensal microbiota on the host metabolism, germ-free (GF) animals, inoculated with individual bacterial strains or complex microbiota, and conventional mice were characterised using 1H NMR spectroscopy and UPLC-MS-based metabolic profiling approaches, and by recording the physiological and immunological parameters. Higher systemic level of (D)-3-hydroxybutyrate and lower levels of circulating VLDL were observed in GF compared to conventional animals, indicating that the absence of gut microbiota stimulated lipolysis while it inhibited hepatic lipogenesis. Subsequently, the best inoculation procedure was obtained by inoculating single bacterial strains into individual animals followed by allowing the animals to exchange their microbes. Metabolic fingerprints showed that a 9 bacteria community is more able to regulate lipoprotein and circulating lipid levels compared to a 3 bacteria community. The origin of the inocula (mouse or human) impacts differently on the host metabolism since humanised mice were strongly disturbed (higher plasma triglyceride level) and displayed metabolic profiles similar to GF mice. Conversely, mouse-associated animals were physiologically, immunologically and metabolically similar to conventional animals. Finally, metabolic profiles and gut microbiota composition were statistically regressed and helped to identify specific bacteria, such as Ruminococcus lactaris and Faecalibacterium prausnitzii, and their putative role in the host homeostasis. To conclude, these results confirmed the influence of gut microbes on the host physiology and metabolism. This PhD thesis provides new insights into the role of gut bacteria to understand the microbial-related mechanisms that participate in the host lipid metabolism, potentially leading to development of obesity.

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.

Gnotobiotics summarizes and analyzes the research conducted on the use of gnotobiotes, providing detailed information regarding actual facility operation and derivation of gnotobiotic animals. In response to the development of new tools for microbiota and microbiome analysis, the increasing recognition of the various roles of microbiota in health and disease, and the consequent expanding demand for gnotobiotic animals for microbiota/microbiome related research, this volume collates the research of this expanding field into one definitive resource. Reviews and defines gnotobiotic animal species Analyzes microbiota in numerous contexts Presents detailed coverage of the protocols and operation of a gnotobiotic facility

This book provides a comprehensive overview of metabonomics and gut microbiota research from molecular analysis to population-based global health considerations. The topics include the discussion of the applications in relation to metabonomics and gut microbiota in nutritional research, in health and disease and a review of future therapeutical, nutraceutical and clinical applications. It also examines the translatability of systems biology approaches into applied clinical research and to patient health and nutrition. The rise in multifactorial disorders, the lack of understanding of the molecular processes at play and the needs for disease prediction in asymptomatic conditions are some of the many questions that system biology approaches are well suited to address. Achieving this goal lies in our ability to model and understand the complex web of interactions between genetics, metabolism, environmental factors and gut microbiota. Being the most densely populated microbial ecosystem on earth, gut microbiota co-evolved as a key component of human biology, essentially extending the physiological definition of humans. Major advances in microbiome research have shown that the contribution of the intestinal microbiota to the overall health status of the host has been so far underestimated. Human host gut microbial interaction is one of the most significant human health considerations of the present day with relevance for both prevention of disease via microbiota-oriented environmental protection as well as strategies for new therapeutic approaches using microbiota as targets and/or biomarkers. In many aspects, humans are not a complete and fully healthy organism without their appropriate microbiological components. Increasingly, scientific evidence identifies gut microbiota as a key biological interface between human genetics and environmental conditions encompassing nutrition. Microbiota dysbiosis or variation in metabolic activity has been associated with metabolic deregulation (e.g. obesity, inflammatory bowel disease), disease risk factor (e.g. coronary heart disease) and even the aetiology of various pathologies (e.g. autism, cancer), although causal role into impaired metabolism still needs to be established. Metabonomics and Gut Microbiota in Nutrition and Disease serves as a handbook for postgraduate students, researchers in life sciences or health sciences, scientists in academic and industrial environments working in application areas as diverse as health, disease, nutrition, microbial research and human clinical medicine.

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In Probiotics, Prebiotics and Synbiotics: Technological Advancements Towards Safety and Industrial Applications, a team of distinguished researchers delivers an insightful exploration of various aspects of functional foods. The book includes information about critical facets of the production of these beneficial compounds, recent technological developments in the field, and their present and future commercial potential. The authors describe their mechanisms of action and their applications in several sectors. Probiotics, Prebiotics and Synbiotics is divided into five parts. A general introduction about these substances begins the book and is followed by discussions of common probiotics, prebiotics, and synbiotics. Finally, a treatment of safety issues and regulatory claims, as well as their market potential, rounds out the resource. Perfect for researchers, industry practitioners, and students working in or studying food processing and food microbiology, Probiotics, Prebiotics and Synbiotics is also an invaluable resource for professionals working in the field of food biotechnology.

Bringing together expert researchers in the fields of microbiome, metabolism, and nutrition research, this book compiles the current state of knowledge from authorities specifically on how diet regulates microbial function with metabolic implications for the human host. Chapters cover the broad concepts of microbial-host interactions under the dietary influences of specific macronutrients, micronutrients, small molecule generation and bile acid circulation, with inclusion of later clinical chapters encompassing topics like bariatric surgery and our current understanding of probiotics, prebiotics, and synbiotics. Covering a timely topic from a functional standpoint, the book fills a gap in the existing literature. While increased attention is placed on descriptive work, it will importantly highlight emerging functional and mechanistic research findings that illustrate the inner workings of the dietary-microbial-host orchestration of metabolic regulation. Providing an exciting summary of the importance of current microbial function, it will also summarize the next major directions in the field of microbiome research.

Microbiota are a promising and fascinating subject in biology because they integrate the microbial communities in humans, animals, plants, and the environment. In humans, microbiota are associated with the gut, skin, and genital, oral, and respiratory organs. The plant microbial community is referred to as "holobiont," and it is influential in the maintenance and health of plants, which themselves play a role in animal health and the environment. The contents of Microbiome-Host Interactions cover all areas as well as new research trends in the fields of plant, animal, human, and environmental microbiome interactions. The book covers microbiota in polar soil environments, in health and disease, in Caenorhabditis elegans, and in agroecosystems, as well as in rice root and actinorhizal root nodules, speleothems, and marine shallow-water hydrothermal vents. Moreover, this book provides comprehensive accounts of advanced next-generation DNA sequencing, metagenomic techniques, high-throughput 16S rRNA sequencing, and understanding nucleic acid sequence data from fungal, algal, viral, bacterial, cyanobacterial, actinobacterial, and archaeal communities using QIIME software (Quantitative Insights into Microbial Ecology). FEATURES Summarizes recent insight in microbiota and host interactions in distinct habitats, including Antarctic, hydrothermal vents, speleothems, oral, skin, gut, feces, reproductive tract, soil, root, root nodules, forests, and mangroves Illustrates the high-throughput amplicon sequencing, computational techniques involved in the microbiota analysis, downstream analysis and visualization, and multivariate analysis commonly used for microbiome analysis Describes probiotics and prebiotics in the composition of the gut microbiota, skin microbiome impact in dermatologic disease prevention, and microbial communities in the reproductive tract of humans and animals Presents information in a reachable way for students, teachers, researchers, microbiologists, computational biologists, and other professionals who are interested in strengthening or enlarging their knowledge about microbiome analysis with next-generation DNA sequencing in the different branches of the sciences