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1.
Effect of Lactoferrin Supplementation on Inflammation, Immune Function, and Prevention of Respiratory Tract Infections in Humans: A Systematic Review and Meta-analysis.
Berthon, BS, Williams, LM, Williams, EJ, Wood, LG
Advances in nutrition (Bethesda, Md.). 2022;13(5):1799-1819
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Human and bovine milk contains Lactoferrin, an iron-binding glycoprotein that may modulate immune function and has antimicrobial and antioxidant properties. In this systematic review and meta-analysis, 25 heterogeneous studies were included to evaluate the efficacy of lactoferrin supplementation on systemic inflammation, immune function, and respiratory tract infections in children and adults with various inflammatory conditions. Supplementation with Lactoferrin reduced only a few inflammatory markers, and beneficial effects were observed in less than half of the studies included. However, a beneficial effect was observed when the intervention was continued for at least three months, and dosages, such as 35 mg/d to 833 mg/d in infants, and 400 mg/d to 600 mg/d in adults, were also found to be beneficial. By modulating the immune system, lactoferrin supplementation reduces respiratory tract infections in children and infants. Based on the findings of this study, healthcare professionals may be able to understand the beneficial effects of Lactoferrin supplementation on immune modulation, inflammation reduction, and respiratory tract infections when supplemented as a combination with other supplements or as Lactoferrin alone. However, it is necessary to conduct further robust research to confirm the clinical effectiveness of Lactoferrin supplementation since the current research is limited in number and heterogeneous in nature.
Abstract
Lactoferrin (Lf) is a glycoprotein present in human and bovine milk with antimicrobial and immune-modulating properties. This review aimed to examine the evidence for the effect of Lf supplementation on inflammation, immune function, and respiratory tract infections (RTIs) in humans. Online databases were searched up to December 2020 to identify relevant, English-language articles that examined the effect of Lf supplementation in human subjects of all ages, on either inflammation, immune cell populations or activity, or the incidence, duration, or severity of respiratory illness or RTIs. Twenty-five studies (n = 20 studies in adults) were included, of which 8 of 13 studies (61%) in adults reported a decrease in at least 1 systemic inflammatory biomarker. Immune function improved in 6 of 8 studies (75%) in adults, with changes in immune cell populations in 2 of 6 studies (33%), and changes in immune cell activity in 2 of 5 studies (40%). RTI outcomes were reduced in 6 of 10 studies (60%) (n = 5 in adults, n = 5 in children), with decreased incidence in 3 of 9 studies (33%), and either decreased frequency (2/4, 50%) or duration (3/6, 50%) in 50% of studies. In adults, Lf reduced IL-6 [mean difference (MD): -24.9 pg/mL; 95% CI: -41.64, -8.08 pg/mL], but not C-reactive protein (CRP) [standardized mean difference: -0.09; 95% CI: -0.82, 0.65], or NK cell cytotoxicity [MD: 4.84%; 95% CI: -3.93, 13.60%]. RTI incidence was reduced in infants and children (OR: 0.78; 95% CI: 0.61, 0.98) but not in adults (OR: 1.00; 95% CI: 0.76, 1.32). Clinical studies on Lf supplementation are limited, although findings show 200 mg Lf/d reduces systemic inflammation, while formulas containing 35-833 mg Lf/d may reduce RTI incidence in infants and children, suggesting improved immune function. Future research is required to determine optimal supplementation strategies and populations most likely to benefit from Lf supplementation. This trial was registered at PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232186) as CRD42021232186.
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Cigarette Smoke Extract Disturbs Mitochondria-Regulated Airway Epithelial Cell Responses to Pneumococci.
Aghapour, M, Tulen, CBM, Abdi Sarabi, M, Weinert, S, Müsken, M, Relja, B, van Schooten, FJ, Jeron, A, Braun-Dullaeus, R, Remels, AH, et al
Cells. 2022;11(11)
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Cigarette smoking can affect airway epithelial cells, causing overproduction of mucus, damage, and inflammation, which may result in the progression of airway diseases. Airway epithelial cells (AEC) rely on mitochondria for energy, and mitochondrial dysfunction may affect innate immunity and the integrity of the airway epithelium. Cigarette smoking is found to accelerate mitochondrial damage within AEC. Maintaining a normal microbial composition within the respiratory tract is essential for maintaining immunity. There is evidence that smoking cigarettes disrupts the microbial composition and increases the spread of pathogenic bacteria such as Streptococcus pneumoniae (Sp) which causes inflammation. By exposing 16HBE cells to Sp and cigarette smoke extract (CSE), this study investigated the effect of cigarette smoking on mitochondrial dysfunction in ACE in an in vitro model. Additionally, the study examined the direct and indirect pathways involved in cigarette smoking-induced mitochondrial dysfunction and altered innate immune response to Sp infection. CSE exposure decreases mitochondrial complex protein levels and mitochondrial membrane potential, which affects energy production. It also increases mitochondrial oxidative stress and mitochondrial degradation. All these factors lead to mitochondrial dysfunction in ACE. CSE exposure to ACE was associated with altered gene expression in the tight and adherence junctions that serve as a protective barrier against pathogens and pollutants and reduced type I interferon immune responses to Sp. Using the results of this study, healthcare professionals can gain a better understanding of the impact of cigarette smoking on mitochondrial dysfunction and how it increases susceptibility to Sp-related immune responses. It is necessary to conduct further studies to evaluate the effects of cigarette smoking on mitochondrial dysfunction, microbial composition disruption, and the interaction between AECs and elevated immune responses.
Abstract
Mitochondrial functionality is crucial for the execution of physiologic functions of metabolically active cells in the respiratory tract including airway epithelial cells (AECs). Cigarette smoke is known to impair mitochondrial function in AECs. However, the potential contribution of mitochondrial dysfunction in AECs to airway infection and airway epithelial barrier dysfunction is unknown. In this study, we used an in vitro model based on AECs exposed to cigarette smoke extract (CSE) followed by an infection with Streptococcus pneumoniae (Sp). The levels of oxidative stress as an indicator of mitochondrial stress were quantified upon CSE and Sp treatment. In addition, expression of proteins associated with mitophagy, mitochondrial content, and biogenesis as well as mitochondrial fission and fusion was quantified. Transcriptional AEC profiling was performed to identify the potential changes in innate immune pathways and correlate them with indices of mitochondrial function. We observed that CSE exposure substantially altered mitochondrial function in AECs by suppressing mitochondrial complex protein levels, reducing mitochondrial membrane potential and increasing mitochondrial stress and mitophagy. Moreover, CSE-induced mitochondrial dysfunction correlated with reduced enrichment of genes involved in apical junctions and innate immune responses to Sp, particularly type I interferon responses. Together, our results demonstrated that CSE-induced mitochondrial dysfunction may contribute to impaired innate immune responses to Sp.
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Probiotics for Immunity – a Look at the Research
OptiBac Probiotics specialise entirely in probiotics. One of their core values is encouraging people to take health into their own hands in a responsible manner. Training and education is a cornerstone of this, and with their expertise, they hope to help raise awareness of probiotics and their potential to help change lives.
2020
Abstract
This blog post presents the evidence available about the links between the gut microbiome, probiotics and the human immune system. With a useful run through of the different aspects of our immune systems, it provides details of the evidence for specific probiotic strains and in what circumstances they can be effectively and safely used to boost immunity.
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The impact of nutrition on COVID-19 susceptibility and long-term consequences.
Butler, MJ, Barrientos, RM
Brain, behavior, and immunity. 2020;87:53-54
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The impacts of Covid-19 are being felt across the world, affecting health, healthcare and economies. Statistics from across the world are showing that the elderly, those with underlying medical conditions and under-represented minority groups are particularly vulnerable to severe complications and have a higher risk of dying of Covid-19. This opinion piece presents arguments for the importance of focusing on diet to support health resilience in general and the immune system in particular, to minimise the impact of this and future viruses. Research is presented on excessive intake of saturated fat leading to chronic activation of the innate immune system (first line, rapid defence against infection), resulting in inflammation, and associated heightened susceptibility to complications of viral infection. The standard western diet (high saturated fat, refined carbohydrates and sugars, low levels of fibre, unsaturated fat and antioxidants) has also been shown to affect the adaptive immune system (second line, delayed defence against infection), depressing its action against infection. The piece also discusses possible long-term, future impacts of those recovered from Covid-19 infection, particularly in relation to neurodegenerative diseases such as Alzheimer’s. The authors call for fresh, healthy wholefoods to be readily available and affordable to everyone in society.
Abstract
While all groups are affected by the COVID-19 pandemic, the elderly, underrepresented minorities, and those with underlying medical conditions are at the greatest risk. The high rate of consumption of diets high in saturated fats, sugars, and refined carbohydrates (collectively called Western diet, WD) worldwide, contribute to the prevalence of obesity and type 2 diabetes, and could place these populations at an increased risk for severe COVID-19 pathology and mortality. WD consumption activates the innate immune system and impairs adaptive immunity, leading to chronic inflammation and impaired host defense against viruses. Furthermore, peripheral inflammation caused by COVID-19 may have long-term consequences in those that recover, leading to chronic medical conditions such as dementia and neurodegenerative disease, likely through neuroinflammatory mechanisms that can be compounded by an unhealthy diet. Thus, now more than ever, wider access to healthy foods should be a top priority and individuals should be mindful of healthy eating habits to reduce susceptibility to and long-term complications from COVID-19.
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Is copper beneficial for COVID-19 patients?
Raha, S, Mallick, R, Basak, S, Duttaroy, AK
Medical hypotheses. 2020;142:109814
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Copper (Cu) is an essential micronutrient that plays an important role in both the innate and adaptive immune response. It has been shown that Cu-deficient humans show increased susceptibility to viral infections. While there is no current vaccine or drug available for the novel coronavirus SARS-CoV-2 (COVID-19), it is critical to identify ways to slow the spread until treatments are found. The aim of this study was to review available data and explore whether increased Cu-levels can boost the immunity in people at risk of COVID-19. While there is a definitive need for clinical trials, the available research does show an association between Cu-deficiency and a weakened immune system. Also, current models for optimal Cu intake indicate that a large portion of the United States population may have Cu-deficiency. Based on this available data, the authors conclude that Cu supplementation may have a protective effect against COVID-19, especially in people at risk for Cu-deficiency.
Abstract
Copper (Cu) is an essential micronutrient for both pathogens and the hosts during viral infection. Cu is involved in the functions of critical immune cells such as T helper cells, B cells, neutrophils natural killer (NK) cells, and macrophages. These blood cells are involved in the killing of infectious microbes, in cell-mediated immunity and the production of specific antibodies against the pathogens. Cu-deficient humans show an exceptional susceptibility to infections due to the decreased number and function of these blood cells. Besides, Cu can kill several infectious viruses such as bronchitis virus, poliovirus, human immunodeficiency virus type 1(HIV-1), other enveloped or nonenveloped, single- or double-stranded DNA and RNA viruses. Moreover, Cu has the potent capacity of contact killing of several viruses, including SARS-CoV-2. Since the current outbreak of the COVID-19 continues to develop, and there is no vaccine or drugs are currently available, the critical option is now to make the immune system competent to fight against the SARS-CoV-2. Based on available data, we hypothesize that enrichment of plasma copper levels will boost both the innate and adaptive immunity in people. Moreover, owing to its potent antiviral activities, Cu may also act as a preventive and therapeutic regime against COVID-19.
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COVID-19 infection: the perspectives on immune responses.
Shi, Y, Wang, Y, Shao, C, Huang, J, Gan, J, Huang, X, Bucci, E, Piacentini, M, Ippolito, G, Melino, G
Cell death and differentiation. 2020;27(5):1451-1454
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The SARS-CoV-2 infection triggers an immune response which varies greatly from one person to another. It can be roughly divided into three stages: stage I, an asymptomatic incubation period with or without detectable virus; stage II, non-severe symptomatic period with the presence of virus; stage III, severe respiratory symptomatic stage with high viral load. Currently around 15% of people infected end up in severe stage III. There appears to be a two-phase immune response; an early protective phase and a second inflammation-driven damaging phase. In phase one the adaptive immune system responds to the virus. Being in good general health is important in this phase to limiting the progression of the disease to a more severe stage. In phase two the innate immune system response to tissue damage caused by the virus could lead to widespread inflammation of the lungs and acute respiratory distress syndrome or respiratory failure. Therapeutically this raises the question of whether the immune response should be boosted in phase one and suppressed in phase two. There also appears to be an element of viral relapse in some patients discharged from hospital indicating that a virus-eliminating immune response may be difficult to achieve naturally. These same patients may also not respond to vaccines. Overall, it is still unclear why some people develop severe disease, whilst others do not. Overall immunity alone does not explain the differences in disease presentation.
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Serological investigation of IgG and IgE antibodies against food antigens in patients with inflammatory bowel disease.
Wang, HY, Li, Y, Li, JJ, Jiao, CH, Zhao, XJ, Li, XT, Lu, MJ, Mao, XQ, Zhang, HJ
World journal of clinical cases. 2019;7(16):2189-2203
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Crohn's disease and ulcerative colitis are relapsing gut inflammatory diseases that are usually referred to as Inflammatory Bowel Disease (IBD). It may be triggered by an imbalance in immune response in response to environmental factors such as diet. The aim of this retrospective study was to evaluate the presence of IgG and IgE mediated antibodies to food antigens in IBD patients. There were one hundred and thirty-seven IBD patients participating in this study, including forty Ulcerative colitis patients and ninety-seven Crohn's disease patients against fifty healthy controls to test serum IgG antibodies to fourteen specific food antigens and serum IgE antibodies to fourteen specific food antigens. There were significantly higher IgG antibodies in response to food antigens in Crohn's disease patients than in Ulcerative colitis patients and healthy controls. Food antigens such as tomato, corn, egg, rice, and soybean exhibited varying levels of IgG antibody responses in Crohn's disease patients and ulcerative colitis patients. Smokers were more likely to develop IgG reactions. Further robust research is needed to examine more IgG-specific food antigens to help manage IBD with an elimination rotation diet. The results of this study can help healthcare professionals understand the importance of diagnosing food intolerances when treating IBD.
Abstract
BACKGROUND Food antigens have been shown to participate in the etiopathogenesis of inflammatory bowel disease (IBD), but their clinical value in IBD is still unclear. AIM: To analyze the levels of specific immunoglobulin G (IgG) and E (IgE) antibodies against food antigens in IBD patients and to determine their clinical value in the pathogenesis of IBD. METHODS We performed a retrospective study based on patients who visited the First Affiliated Hospital of Nanjing Medical University between August 2016 and January 2018. A total of 137 IBD patients, including 40 patients with ulcerative colitis (UC) and 97 patients with Crohn's disease (CD), and 50 healthy controls (HCs), were recruited. Serum food-specific IgG antibodies were detected by semi-quantitative enzyme-linked immunosorbent assay, and serum food-specific IgE antibodies were measured by Western blot. The value of food-specific IgG antibodies was compared among different groups, and potent factors related to these antibodies were explored by binary logistic regression. RESULTS Food-specific IgG antibodies were detected in 57.5% of UC patients, in 90.72% of CD patients and in 42% of HCs. A significantly high prevalence and titer of food-specific IgG antibodies were observed in CD patients compared to UC patients and HCs. The number of IgG-positive foods was greater in CD and UC patients than in HCs (CD vs HCs, P = 0.000; UC vs HCs, P = 0.029). The top five food antigens that caused positive specific IgG antibodies in CD patients were tomato (80.68%), corn (69.32%), egg (63.64%), rice (61.36%), and soybean (46.59%). The foods that caused positive specific IgG antibodies in UC patients were egg (60.87%), corn (47.83%), tomato (47.83%), rice (26.09%), and soybean (21.74%). Significantly higher levels of total food-specific IgG were detected in IBD patients treated with anti-TNFα therapy compared to patients receiving steroids and immunosuppressants (anti-TNFα vs steroids, P = 0.000; anti-TNFα vs immunosuppressants, P = 0.000; anti-TNFα vs steroids + immunosuppressants, P = 0.003). A decrease in food-specific IgG levels was detected in IBD patients after receiving anti-TNFα therapy (P = 0.007). Patients who smoked and CD patients were prone to developing serum food-specific IgG antibodies [Smoke: OR (95%CI): 17.6 (1.91-162.26), P = 0.011; CD patients: OR (95%CI): 12.48 (3.45-45.09), P = 0.000]. There was no difference in the prevalence of food-specific IgE antibodies among CD patients (57.1%), UC patients (65.2%) and HCs (60%) (P = 0.831). CONCLUSION CD patients have a higher prevalence of food-specific IgG antibodies than UC patients and HCs. IBD patients are prone to rice, corn, tomato and soybean intolerance. Smoking may be a risk factor in the occurrence of food-specific IgG antibodies. Food-specific IgG antibodies may be a potential method in the diagnosis and management of food intolerance in IBD.
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The Sleep-Immune Crosstalk in Health and Disease.
Besedovsky, L, Lange, T, Haack, M
Physiological reviews. 2019;99(3):1325-1380
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The interaction between sleep and immunity is an established phenomena. This thorough review article summarises sleep changes in response to both infectious and non-infectious immune system challenges and describes the role of sleep in supporting the immune system. Details are provided of how sleep affects the innate immune system (first line, rapid defence against infection) as well as the adaptive immune system (second line, delayed defence against infection), using a feedback system which promotes host defence. Sleep is associated with reduced infection risk and can improve infection outcome and vaccination responses. Sleep deprivation is also associated with chronic, low-grade inflammation. Nutrition Practitioners wishing to support immunity can focus on sleep as a simple lifestyle measure to enhance resilience.
Abstract
Sleep and immunity are bidirectionally linked. Immune system activation alters sleep, and sleep in turn affects the innate and adaptive arm of our body's defense system. Stimulation of the immune system by microbial challenges triggers an inflammatory response, which, depending on its magnitude and time course, can induce an increase in sleep duration and intensity, but also a disruption of sleep. Enhancement of sleep during an infection is assumed to feedback to the immune system to promote host defense. Indeed, sleep affects various immune parameters, is associated with a reduced infection risk, and can improve infection outcome and vaccination responses. The induction of a hormonal constellation that supports immune functions is one likely mechanism underlying the immune-supporting effects of sleep. In the absence of an infectious challenge, sleep appears to promote inflammatory homeostasis through effects on several inflammatory mediators, such as cytokines. This notion is supported by findings that prolonged sleep deficiency (e.g., short sleep duration, sleep disturbance) can lead to chronic, systemic low-grade inflammation and is associated with various diseases that have an inflammatory component, like diabetes, atherosclerosis, and neurodegeneration. Here, we review available data on this regulatory sleep-immune crosstalk, point out methodological challenges, and suggest questions open for future research.
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Microbiome-Gut-Brain Axis and Toll-Like Receptors in Parkinson's Disease.
Caputi, V, Giron, MC
International journal of molecular sciences. 2018;19(6)
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Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease and recently the role of the microbiota-gut-brain axis has gained attention in patients with PD. Research shows that an altered gut microbiota can activate Toll-like receptors (TLRs), receptors involved in the innate immune response, causing an inflammatory cascade in the gut and brain. Based on this knowledge, gut microbiota and TLRs may be potential therapeutic targets for PD. This review sheds light on the current knowledge regarding the association between the microbiota-gut-brain axis and innate immunity via TLR signalling in PD. Increased understanding of this relationship should lead to insights on the pathophysiology of PD, as well as improved dietary and pharmaceutical therapeutic approaches in PD patients. Based on the existing evidence, the authors conclude that through modulating the gut, thus balancing the immune response in PD patients, it may be possible to influence early phases of the neurodegenerative cascade.
Abstract
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease characterized by α-synucleinopathy, which involves all districts of the brain-gut axis, including the central, autonomic and enteric nervous systems. The highly bidirectional communication between the brain and the gut is markedly influenced by the microbiome through integrated immunological, neuroendocrine and neurological processes. The gut microbiota and its relevant metabolites interact with the host via a series of biochemical and functional inputs, thereby affecting host homeostasis and health. Indeed, a dysregulated microbiota-gut-brain axis in PD might lie at the basis of gastrointestinal dysfunctions which predominantly emerge many years prior to the diagnosis, corroborating the theory that the pathological process is spread from the gut to the brain. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognizing conserved motifs primarily found in microorganisms and a dysregulation in their signaling may be implicated in α-synucleinopathy, such as PD. An overstimulation of the innate immune system due to gut dysbiosis and/or small intestinal bacterial overgrowth, together with higher intestinal barrier permeability, may provoke local and systemic inflammation as well as enteric neuroglial activation, ultimately triggering the development of alpha-synuclein pathology. In this review, we provide the current knowledge regarding the relationship between the microbiota-gut⁻brain axis and TLRs in PD. A better understanding of the dialogue sustained by the microbiota-gut-brain axis and innate immunity via TLR signaling should bring interesting insights in the pathophysiology of PD and provide novel dietary and/or therapeutic measures aimed at shaping the gut microbiota composition, improving the intestinal epithelial barrier function and balancing the innate immune response in PD patients, in order to influence the early phases of the following neurodegenerative cascade.
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The microbiome and autoimmunity: a paradigm from the gut-liver axis.
Li, B, Selmi, C, Tang, R, Gershwin, ME, Ma, X
Cellular & molecular immunology. 2018;15(6):595-609
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The incidence of autoimmune and inflammatory diseases has been increasing worldwide. Changes in environmental factors, such as modern lifestyle, diet, antibiotics and hygiene are thought to play a critical role in the development of various autoimmune diseases. It is the mucosal microbial flora that is shaped by our environment and communicates with the innate and adaptive immune systems, and when disrupted, can lead to the loss of immune tolerance and dysregulated immune cells. This review paper provides an overview of the interactions between the intestinal microbiome and the immune system. It explains how these interactions affect host autoimmunity locally and systemically and sheds light on the molecular mechanisms, utilised by microbes that may contribute to systemic autoimmunity in genetically susceptible individuals. The links between the gut microbiome and various autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes and multiple sclerosis, as well as the gut-liver axis, involving intestinal microbiome and autoimmune liver diseases, are discussed in more detail.
Abstract
Microbial cells significantly outnumber human cells in the body, and the microbial flora at mucosal sites are shaped by environmental factors and, less intuitively, act on host immune responses, as demonstrated by experimental data in germ-free and gnotobiotic studies. Our understanding of this link stems from the established connection between infectious bacteria and immune tolerance breakdown, as observed in rheumatic fever triggered by Streptococci via molecular mimicry, epitope spread and bystander effects. The availability of high-throughput techniques has significantly advanced our capacity to sequence the microbiome and demonstrated variable degrees of dysbiosis in numerous autoimmune diseases, including rheumatoid arthritis, type 1 diabetes, multiple sclerosis and autoimmune liver disease. It remains unknown whether the observed differences are related to the disease pathogenesis or follow the therapeutic and inflammatory changes and are thus mere epiphenomena. In fact, there are only limited data on the molecular mechanisms linking the microbiota to autoimmunity, and microbial therapeutics is being investigated to prevent or halt autoimmune diseases. As a putative mechanism, it is of particular interest that the apoptosis of intestinal epithelial cells in response to microbial stimuli enables the presentation of self-antigens, giving rise to the differentiation of autoreactive Th17 cells and other T helper cells. This comprehensive review will illustrate the data demonstrating the crosstalk between intestinal microbiome and host innate and adaptive immunity, with an emphasis on how dysbiosis may influence systemic autoimmunity. In particular, a gut-liver axis involving the intestinal microbiome and hepatic autoimmunity is elucidated as a paradigm, considering its anatomic and physiological connections.