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 is the first comprehensive volume to look at the importance of short-chain fatty acids in digestion, the function of the large intestine and their role in human health. Short-chain fatty acids are the major product of bacterial fermentation of dietary carbohydrates in the human and animal large intestine. They represent the major end products of digestive processes occurring in the caecum and large intestine. As such, they form an important dietary component and it is increasingly recognised that they may have a significant role in protecting against large bowel cancer and in metabolism. Prepared by an international team of contributors who are at the forefront of this area of research, this volume will be an essential source of reference for gastroenterologists, nutritionists and others active in this area.

[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.]

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.

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.

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.