The role of immune system maturation in gut-microbiota-brain axis communication

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.

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The interplay between gut microbiota and the immune system in liver transplant recipients and its role in infections

Infection and Immunity ◽

10.1128/iai.00376-21 ◽

2021 ◽

Author(s):

Giuseppe Ancona ◽

Laura Alagna ◽

Andrea Lombardi ◽

Emanuele Palomba ◽

Valeria Castelli ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Immune System ◽

Liver Disease ◽

Gut Microbiota ◽

Liver Transplant ◽

Bacterial Infections ◽

Multidrug Resistant ◽

Transplant Recipients ◽

Liver Transplant Recipients

Liver transplantation (LT) is a life-saving strategy for patients with end-stage liver disease, hepatocellular carcinoma and acute liver failure. LT success can be hampered by several short-term and long-term complications. Among them, bacterial infections, especially due to multidrug-resistant germs, are particularly frequent with a prevalence between 19 and 33% in the first 100 days after transplantation. In the last decades, a number of studies have highlighted how gut microbiota (GM) is involved in several essential functions to ensure the intestinal homeostasis, becoming one of the most important virtual metabolic organs. GM works through different axes with other organs, and the gut-liver axis is among the most relevant and investigated ones. Any alteration or disruption of GM is defined as dysbiosis. Peculiar phenotypes of GM dysbiosis have been associated to several liver conditions and complications, such as chronic hepatitis, fatty liver disease, cirrhosis and hepatocellular carcinoma. Moreover, there is growing evidence of the crucial role of GM in shaping the immune response, both locally and systemically, against pathogens. This paves the way to the manipulation of GM as a therapeutic instrument to modulate the infectious risk and outcome. In this minireview we provide an overview of the current understanding on the interplay between gut microbiota and the immune system in liver transplant recipients and the role of the former in infections.

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ON THE QUESTION OF THE PATHOGENESIS OF HIV-INFECTION: THE ROLE OF IMMUNE ACTIVATION IN PROGRESSION OF DISEASE

Epidemiology and Infectious Diseases (Russian Journal) ◽

10.17816/eid40663 ◽

2012 ◽

Vol 17 (3) ◽

pp. 47-52

Author(s):

G. R. Khasanova ◽

I. G. Mustafin ◽

V. A. Anokhin

Keyword(s):

Immune System ◽

Gut Microbiota ◽

Hiv Infection ◽

Immune Activation ◽

Opportunistic Pathogens ◽

Rate Of Progression ◽

Progression Of Disease ◽

Modern Knowledge

Hyperactivaion of immme system is considered by most investigators as importantfactor, contributing to progression of HIV-infection and development ofAIDS. In the review modern knowledge about mechanisms and results of activation of immune system during HIV-infection are presented. HIV itself, opportunistic pathogens and components of gut microbiota, first of all, endotoxins ofgram-negative bacteria are considered as probable "activators" of immune system. High levels of endotoxin and markers of immune activation are associated with an even greater rate of progression of HIV-infection.

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Sepsis and the Microbiome: A Vicious Cycle

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa682 ◽

2020 ◽

Author(s):

William D Miller ◽

Robert Keskey ◽

John C Alverdy

Keyword(s):

Immune Response ◽

Immune System ◽

Gut Microbiota ◽

Enteral Feeding ◽

Gut Microbiome ◽

Antibiotic Stewardship ◽

Vicious Cycle ◽

Fecal Transplant ◽

Suspected Infection

Abstract Although sepsis has been characterized as a dysregulated immune response to an ongoing or suspected infection, the role of the microbiome as a key influencer of the septic response is emerging. The unavoidable disruption of the microbiome while treating sepsis with antibiotics can itself result in immune system dysregulation, further exacerbating the course and outcome of sepsis. Alterations in the gut microbiome as a result of sepsis and its treatment have been implicated in the organ dysfunction typical of sepsis across a wide variety of tissues including the lung, kidney and brain. A number of microbiota directed interventions are currently under investigation in the setting of sepsis including fecal transplant, the administration of dietary fiber in enteral feeding products and the use of antibiotic scavengers that are directed at attenuating the effects of antibiotics on the gut microbiota while allowing them to concentrate at the primary sites of infection. Taken together, the emerging role of the gut microbiome in sepsis touches various elements of the pathophysiology of sepsis and its treatment, and provides yet another reason to consider the judicious use of antibiotics via antibiotic stewardship programs.

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The Gut Microbiota in Multiple Sclerosis: An Overview of Clinical Trials

Cell Transplantation ◽

10.1177/0963689719873890 ◽

2019 ◽

Vol 28 (12) ◽

pp. 1507-1527 ◽

Cited By ~ 16

Author(s):

Giovanni Schepici ◽

Serena Silvestro ◽

Placido Bramanti ◽

Emanuela Mazzon

Keyword(s):

Multiple Sclerosis ◽

Immune System ◽

Gut Microbiota ◽

Fecal Microbiota Transplantation ◽

Fecal Microbiota ◽

System A ◽

Relapsing Remitting ◽

The Central Nervous System ◽

Review Reports

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, and degenerative disease that affects the central nervous system. A recent study showed that interaction between the immune system and the gut microbiota plays a crucial role in the development of MS. This review reports the clinical studies carried out in recent years that aimed to evaluate the composition of the microbiota in patients with relapsing–remitting MS (RR-MS). We also report what is available in the literature regarding the effectiveness of fecal microbiota transplantation and the role of the diet in restoring the intestinal bacterial population. Studies report that patients with RR-MS have a microbiota that, compared with healthy controls, has higher amounts of Pedobacteria, Flavobacterium, Pseudomonas, Mycoplana, Acinetobacter, Eggerthella, Dorea, Blautia, Streptococcus and Akkermansia. In contrast, MS patients have a microbiota with impoverished microbial populations of Prevotella, Bacteroides, Parabacteroides, Haemophilus, Sutterella, Adlercreutzia, Coprobacillus, Lactobacillus, Clostridium, Anaerostipes and Faecalibacterium. In conclusion, the restoration of the microbial population in patients with RR-MS appears to reduce inflammatory events and the reactivation of the immune system.

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Immunomodulation by Gut Microbiota: Role of Toll-Like Receptor Expressed by T Cells

Journal of Immunology Research ◽

10.1155/2014/586939 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 23

Author(s):

Mariagrazia Valentini ◽

Alessia Piermattei ◽

Gabriele Di Sante ◽

Giuseppe Migliara ◽

Giovanni Delogu ◽

...

Keyword(s):

T Cells ◽

Immune System ◽

Gut Microbiota ◽

Cell Types ◽

Mutual Regulation ◽

Close Relationship ◽

Numerous Cell ◽

Specific Receptors ◽

And Function

A close relationship exists between gut microbiota and immune responses. An imbalance of this relationship can determine local and systemic immune diseases. In fact the immune system plays an essential role in maintaining the homeostasis with the microbiota that normally resides in the gut, while, at the same time, the gut microbiota influences the immune system, modulating number and function of effector and regulatory T cells. To achieve this aim, mutual regulation between immune system and microbiota is achieved through several mechanisms, including the engagement of toll-like receptors (TLRs), pathogen-specific receptors expressed on numerous cell types. TLRs are able to recognize ligands from commensal or pathogen microbiota to maintain the tolerance or trigger the immune response. In this review, we summarize the latest evidences about the role of TLRs expressed in adaptive T cells, to understand how the immune system promotes intestinal homeostasis, fights invasion by pathogens, and is modulated by the intestinal microbiota.

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The Multifaceted Effects of Gut Microbiota on the Immune System of the Intestinal Mucosa

Immuno ◽

10.3390/immuno1040041 ◽

2021 ◽

Vol 1 (4) ◽

pp. 583-594

Author(s):

Takehiro Hirano ◽

Hiroshi Nakase

Keyword(s):

Immune System ◽

Gut Microbiota ◽

Gut Microbiome ◽

Mucosal Barrier ◽

Host Immune System ◽

Immunological Responses ◽

Gut Homeostasis ◽

Inflammatory Processes ◽

And Oxidative Stress

The gut microbiota has diverse microbial components, including bacteria, viruses, and fungi. The interaction between gut microbiome components and immune responses has been studied extensively over the last decade. Several studies have reported the potential role of the gut microbiome in maintaining gut homeostasis and the development of disease. The commensal microbiome can preserve the integrity of the mucosal barrier by acting on the host immune system. Contrastingly, dysbiosis-induced inflammation can lead to the initiation and progression of several diseases through inflammatory processes and oxidative stress. In this review, we describe the multifaceted effects of the gut microbiota on several diseases from the perspective of mucosal immunological responses.

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Physical activity regulates the intestinal microbiota composition

Annales Kinesiologiae ◽

10.35469/ak.2019.185 ◽

2019 ◽

Vol 10 (2) ◽

pp. 99-114

Author(s):

Mihaela Jurdana ◽

Darja Barlič-Maganja

Keyword(s):

Physical Activity ◽

Psychological Distress ◽

Immune System ◽

Health Status ◽

Gut Microbiota ◽

Bacterial Population ◽

Microbiota Composition ◽

Scientific Attention ◽

Communication Pathway

Gut microbiota is the name given today to the bacterial population living in our intestine. It provides nutrients, metabolites and affects the immune system. Recent animals and human studies suggest that regular physical activity increases the presence of beneficial microbial species of gut microbiota and improves the health status of the host. When gut bacteria diversity reduces, there are systemic consequences leading to gastrointestinal, physiological and psychological distress. This review describes the communication pathway of the microbiota-gut-brain axes and other possible mechanisms by which physical activity causes changes in microbiota composition. Furthermore, it provides the latest evidence of the beneficial role of exercise, which in turn can affect health and various disease processes. The results of research studies in this area are increasingly becoming a focus of scientific attention.

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The role of Lactic Acid Bacteria in Gut Microbiota and Mucosal Immune System

South Florida Journal of Development ◽

10.46932/sfjdv2n3-009 ◽

2021 ◽

Vol 2 (3) ◽

pp. 3818-3825

Author(s):

Siyu Lu

Keyword(s):

Immune System ◽

Gut Microbiota ◽

Dietary Supplementation ◽

Fermented Food ◽

Natural Food ◽

System Function ◽

Beneficial Effects ◽

Immune System Function ◽

Excessive Consumption

In recent years, nutritionists and microbiologists have paid more attention to the utilization of dietary supplementation produced by natural food resources, to improve the immune system function of the human and animals. People are more willing to obtain nature supplementations due to the growing awareness of food safety, and the side effects of excessive consumption of manufactured supplements. Fermented food are introduced to provide beneficial effects on health because of the characteristics of LAB, which are temporary integrative microorganisms in the intestinal microbiota. And they could not only balance the micro-ecosystem of the host by secreting microbiome, but also enhance the beneficial properties of autonomous microorganisms. This review aims to discuss the of LAB yogurt to the gut microbiota based on recent research.

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The Role of Gut Microbiota in Tumor Immunotherapy

Journal of Immunology Research ◽

10.1155/2021/5061570 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Miao Wu ◽

Jiawei Bai ◽

Chengtai Ma ◽

Jie Wei ◽

Xianjin Du

Keyword(s):

Immune System ◽

Gut Microbiota ◽

Intestinal Microbiota ◽

Adverse Reactions ◽

Tumor Development ◽

Tumor Immunotherapy ◽

Host Immune System ◽

Hematological Tumors ◽

New Research

Tumor immunotherapy is the fourth therapy after surgery, chemotherapy, and radiotherapy. It has made great breakthroughs in the treatment of some epithelial tumors and hematological tumors. However, its adverse reactions are common or even more serious, and the response rate in some solid tumors is not satisfactory. With the maturity of genomics and metabolomics technologies, the effect of intestinal microbiota in tumor development and treatment has gradually been recognized. The microbiota may affect tumor immunity by regulating the host immune system and tumor microenvironment. Some bacteria help fight tumors by activating immunity, while some bacteria mediate immunosuppression to help cancer cells escape from the immune system. More and more studies have revealed that the effects and complications of tumor immunotherapy are related to the composition of the gut microbiota. The composition of the intestinal microbiota that is sensitive to treatment or prone to adverse reactions has certain characteristics. These characteristics may be used as biomarkers to predict the prognosis of immunotherapy and may also be developed as “immune potentiators” to assist immunotherapy. Some clinical and preclinical studies have proved that microbial intervention, including microbial transplantation, can improve the sensitivity of immunotherapy or reduce adverse reactions to a certain extent. With the development of gene editing technology and nanotechnology, the design and development of engineered bacteria that contribute to immunotherapy has become a new research hotspot. Based on the relationship between the intestinal microbiota and immunotherapy, the correct mining of microbial information and the development of reasonable and feasible microbial intervention methods are expected to optimize tumor immunotherapy to a large extent and bring new breakthroughs in tumor treatment.

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