[Increasing evidence suggests that microbiota and especially the gut microbiota (the microbes inhabiting the gut including bacteria, archaea, viruses, and fungi) plays a key role in human physiology and pathology. Recent findings indicate how dysbiosis—an imbalance in the composition and organization of microbial populations—could severely impact the development of different medical conditions (from metabolic to mood disorders), providing new insights into the comprehension of diverse diseases, such as IBD, obesity, asthma, autism, stroke, diabetes, and cancer. Given that microbial cells in the gut outnumber host cells, microbiota influences human physiology both functionally and structurally. Microbial metabolites bridge various—even distant—areas of the organism by way of the immune and hormone system. For instance, it is now clear that the mutual interaction between the gastrointestinal tract and the brain (gut–brain axis), often involves gut microbiota, indicating that the crosstalk between the organism and its microbial residents represents a fundamental aspect of both the establishment and maintenance of healthy conditions. Moreover, it is crucial to recognize that beyond the intestinal tract, microbiota populates other host organs and tissues (e.g., skin and oral mucosa). We have edited this eBook with the aim of publishing manuscripts focusing on the impact of microbiota in the development of different diseases and their associated treatments.]

[Increasing evidence suggests that microbiota and especially the gut microbiota (the microbes inhabiting the gut including bacteria, archaea, viruses, and fungi) plays a key role in human physiology and pathology. Recent findings indicate how dysbiosis-an imbalance in the composition and organization of microbial populations-could severely impact the development of different medical conditions (from metabolic to mood disorders), providing new insights into the comprehension of diverse diseases, such as IBD, obesity, asthma, autism, stroke, diabetes, and cancer. Given that microbial cells in the gut outnumber host cells, microbiota influences human physiology both functionally and structurally. Microbial metabolites bridge various-even distant-areas of the organism by way of the immune and hormone system. For instance, it is now clear that the mutual interaction between the gastrointestinal tract and the brain (gut-brain axis), often involves gut microbiota, indicating that the crosstalk between the organism and its microbial residents represents a fundamental aspect of both the establishment and maintenance of healthy conditions. Moreover, it is crucial to recognize that beyond the intestinal tract, microbiota populates other host organs and tissues (e.g., skin and oral mucosa). We have edited this eBook with the aim of publishing manuscripts focusing on the impact of microbiota in the development of different diseases and their associated treatments.].

The composition of gut microbiota plays a critical role in maintaining the host's health, particularly in regulating immune homeostasis and the intestinal immune response. A massive effort has pointed to the importance of these interactions in various intestinal diseases like colorectal cancer (CRC), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD). Microbiome influences the formation of key components of both the innate and adaptive immune systems, while the immune system is responsible for regulating and maintaining the symbiotic relationship between the host and microbes. Currently, the crosstalk between gut flora and host immunity is not fully revealed in both homeostasis maintenance and disease development. Hence detailed mechanistic studies are needed to further explore the microbial manipulation on host immunity as well as the immune response to microbiome dysbiosis in intestinal diseases. Current evidence indicates a strong bidirectional interaction between microbiome perturbation and immune dysregulation. The aim of this Research Topic is to create a platform for the advancement of research on the causal relationship between the microbiome and immunity. Besides, we would like to define the core microbiota responsible for the initiation and progression of intestinal diseases, the molecular mechanisms of host immune-microbiome interactions, and novel gut-targeted pharmacological interventions to achieve a positive impact on intestinal disease.

This work sheds new light on the interplay between the gut, gut microbiota, and host physiological processes in production animals. The gut microbiome shapes health and susceptibility to disease and has become a leading area of research in the animal sciences. Gut health encompasses a number of physiological and functional features. Nutrient digestion and absorption, host metabolism and energy generation, a stable microbiome, mucus layer development, barrier function, and mucosal immune responses; all of which are required to interact to make an animal perform physiologically and according to its greatest genetic potential. This carefully presented book broadens our vision, approach and results on gut health and the ability to regulate animal production. Understanding the chemistry of microbiomes has broad implications, including providing functional annotations for the microbial genomes, insights into the chemical languages that link microbes to each other and to their host, and translational implications for precision veterinary medicine, environmental health, and sustainable animal agriculture and welfare. Experts working in microbiome research, host immunity, and animal production, veterinarians and researchers in livestock science will understand the great importance of this volume.

Why the microbiome--our rich inner ecosystem of microorganisms--may hold the keys to human health. We are at the dawn of a new scientific revolution. Our understanding of how to treat and prevent diseases has been transformed by knowledge of the microbiome—the rich ecosystem of microorganisms in and on every human. These microbial hitchhikers may hold the keys to human health. In Gut Feelings, Alessio Fasano and Susie Flaherty show why we must go beyond the older, myopic view of microorganisms as our enemies to a broader understanding of the microbiome as a parallel civilization that we need to understand, respect, and engage with for the benefit of our own health. Recent advances in understanding the microbiome and its role in human health dovetail with the development of personalized or “precision” medicine to create treatments and prevention programs targeted to the molecular imprint of an individual. Fasano and Flaherty explore the microbiome's part in such diseases as gut inflammatory disorders, obesity, neurological conditions, and cancer, and they explain new research in prebiotics, probiotics, synbiotics, and psychobiotics. They also discuss the microbiome and immune function, including a possible role in COVID-19 treatment. By simultaneously expanding our perspective to encompass large datasets and multiple factors in human health, and narrowing our focus to identify the individual communities in the human microbiome, we will enlarge—and perhaps reinvent—our understanding of how to combat disease and maintain health.

Microbial endocrinology represents a newly emerging interdisciplinary field that is formed by the intersection of the fields of neurobiology and microbiology. This book will introduce a new perspective to the current understanding not only of the factors that mediate the ability of microbes to cause disease, but also to the mechanisms that maintain normal homeostasis. The discovery that microbes can directly respond to neuroendocrine hormones, as evidenced by increased growth and production of virulence-associated factors, provides for a new framework with which to investigate how microorganisms interface not only with vertebrates, but also with invertebrates and even plants. The reader will learn that the neuroendocrine hormones that one most commonly associates with mammals are actually found throughout the plant, insect and microbial communities to an extent that will undoubtedly surprise many, and most importantly, how interactions between microbes and neuroendocrine hormones can influence the pathophysiology of infectious disease.