Microbiota, Immune Subversion, and Chronic Inflammation

Exploring the Relationship Between Sporadic Creutzfeldt-Jakob Disease and Gut Microbiota Through a Mendelian Randomization Study

Observational studies have shown gut microbiota changes in sporadic Creutzfeldt-Jakob disease patients, but the causal relationship remains unknown. We aimed to determine any causal links between gut microbiota and this prion disease. Using Mendelian randomization analysis, we examined the causal relationship between gut microbiota composition and sporadic Creutzfeldt-Jakob disease. Data on gut microbiota (N = 18,340) and disease cases (5208) were obtained. Various analysis methods were used, including inverse variance weighted, Mendelian randomization-Egger, weighted median, simple mode, and weighted mode. In addition, MR-PRESSO was used to evaluate horizontal pleiotropy and detect outliers. Pleiotropy and heterogeneity were assessed, and reverse analysis was conducted. Negative associations were found between sporadic Creutzfeldt-Jakob disease and family Defluviitaleaceae, family Ruminococcaceae, genus Butyricicoccus, genus Desulfovibrio, and genus Eubacterium nodatum. Genus Lachnospiraceae UCG010 showed a positive correlation. Reverse analysis indicated genetic associations between the disease and decreased levels of family Peptococcaceae, genus Faecalibacterium, and genus Phascolarctobacterium, as well as increased levels of genus Butyrivibrio. No pleiotropy, heterogeneity, outliers, or weak instrument bias were observed. This study revealed bidirectional causal effects between specific gut microbiota components and sporadic Creutzfeldt-Jakob disease. Certain components demonstrated inhibitory effects on disease pathogenesis, while others were positively associated with the disease. Modulating gut microbiota may provide new insights into prion disease therapies. Further research is needed to clarify mechanisms and explore treatments for sporadic Creutzfeldt-Jakob disease.

Interspecific differences and mechanisms of Lactobacillus-derived anti-inflammatory exopolysaccharides

Accumulating evidence has revealed the anti-inflammatory properties of Lactobacillus-derived exopolysaccharides (EPSs). However, interspecific differences among these Lactobacillus-derived anti-inflammatory EPSs have not been investigated. Cell experiments showed that Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum-derived EPSs exhibited excellent anti-inflammatory efficacy in vitro. Subsequently, we used Lactobacillus-derived EPSs to treat colitis in mice. There was no significant difference in EPS's repair of the intestinal barrier from the five Lactobacillus species. However, Ligilactobacillus salivarius-derived EPSs and L. plantarum-derived EPSs more potently reduced proinflammatory cytokines (TNF-α, IL-1β, IL-6, TNF-γ, and IL-17), increasing IL-10 concentrations in the colon. Lactobacillus-derived EPS moieties from five species regulate intestinal bacteria at the strain level. Immunofluorescence staining revealed that owing to the different infiltration and polarization effects of Lactobacillus-derived EPSs on macrophages, the in vitro and in vivo anti-inflammatory effects of Lactobacillus-derived EPSs were inconsistent. The structure-activity relationship showed that Lactobacillus-derived EPSs with high fructose content had excellent anti-inflammatory activity in vivo. The results mentioned above revealed that the anti-inflammatory activity of Lactobacillus-derived EPSs had interspecific variability, and the mechanism of anti-inflammatory action in vitro and in vivo was different.

Chronic periodontitis and risk of cerebro-cardiovascular diseases among older Koreans

BACKGROUND AND OBJECTIVE

There is a relative lack of evidence from observational studies of older populations investigating the association between chronic periodontitis and cerebro-cardiovascular diseases. Accordingly, we investigated the risk of cerebro-cardiovascular diseases according to the severity of chronic periodontitis among older adults.

METHODS

Data on older adults with chronic periodontitis were extracted from the Korea National Health Insurance Service-Senior Cohort Database using diagnosis codes and dental procedures. Participants were divided into two exposure groups. Among 46 737 participants eligible for inclusion, 21 905 (46.9%) had newly diagnosed mild chronic periodontitis, and 24 832 (53.1%) had newly diagnosed severe chronic periodontitis. To determine the risk of cerebro-cardiovascular diseases, including ischemic stroke, haemorrhagic stroke, and myocardial infarction, multivariable-adjusted Cox proportional hazards modelling was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) in this retrospective follow-up study.

RESULTS

A total of 3453 (7.4%) outcomes were identified during a mean follow-up of 6.1 years. Kaplan-Meier analysis revealed that disease-free probability was lower in the severe group than in the mild group (log-rank P < .001). In the multivariable-adjusted model, the HR for cerebro-cardiovascular diseases in the severe group (relative to the mild group) was 1.16 (95% CI: 1.09-1.25). In individual outcome analysis, ischemic stroke and myocardial infarction were associated with chronic periodontitis severity, but haemorrhagic stroke was not.

CONCLUSION

The severity of chronic periodontitis could be associated with the risk of cerebro-cardiovascular diseases in older adults.

Dietary administration of the glycolytic inhibitor 2-deoxy-D-glucose reduces endotoxemia-induced inflammation and oxidative stress: Implications in PAMP-associated acute and chronic pathology

Pathogen-associated molecular patterns (PAMPs) like bacterial cell wall components and viral nucleic acids are known ligands of innate inflammatory receptors that trigger multiple inflammatory pathways that may result in acute inflammation and oxidative stress-driven tissue and organ toxicity. When dysregulated, this inflammation may lead to acute toxicity and multiorgan failure. Inflammatory events are often driven by high energy demands and macromolecular biosynthesis. Therefore, we proposed that targeting the metabolism of lipopolysaccharide (LPS)-driven inflammatory events, using an energy restriction approach, can be an effective strategy to prevent the acute or chronic detrimental effects of accidental or seasonal bacterial and other pathogenic exposures. In the present study, we investigated the potential of energy restriction mimetic agent (ERMA) 2-deoxy-D-glucose (2-DG) in targeting the metabolism of inflammatory events during LPS-elicited acute inflammatory response. Mice fed with 2-DG as a dietary component in drinking water showed reduced LPS-driven inflammatory processes. Dietary 2-DG reduced LPS-induced lung endothelial damage and oxidative stress by strengthening the antioxidant defense system and limiting the activation and expression of inflammatory proteins, viz., P-Stat-3, NfκΒ, and MAP kinases. This was accompanied by decreased TNF, IL-1β, and IL-6 levels in peripheral blood and bronchoalveolar lavage fluid (BALF). 2-DG also reduced the infiltration of PMNCs (polymorphonuclear cells) in inflamed tissues. Altered glycolysis and improved mitochondrial activity in 2-DG-treated RAW 264.7 macrophage cells suggested possible impairment of macrophage metabolism and, therefore, activation in macrophages. Taken together, the present study suggests that inclusion of glycolytic inhibitor 2-DG as a part of the diet can be helpful in preventing the severity and poor prognosis associated with inflammatory events during bacterial and other pathogenic exposures.

Porphyromonas gingivalis regulates atherosclerosis through an immune pathway

Atherosclerosis (AS) is a chronic inflammatory disease, involving a pathological process of endothelial dysfunction, lipid deposition, plaque rupture, and arterial occlusion, and is one of the leading causes of death in the world population. The progression of AS is closely associated with several inflammatory diseases, among which periodontitis has been shown to increase the risk of AS. Porphyromonas gingivalis (P. gingivalis), presenting in large numbers in subgingival plaque biofilms, is the “dominant flora” in periodontitis, and its multiple virulence factors are important in stimulating host immunity. Therefore, it is significant to elucidate the potential mechanism and association between P. gingivalis and AS to prevent and treat AS. By summarizing the existing studies, we found that P. gingivalis promotes the progression of AS through multiple immune pathways. P. gingivalis can escape host immune clearance and, in various forms, circulate with blood and lymph and colonize arterial vessel walls, directly inducing local inflammation in blood vessels. It also induces the production of systemic inflammatory mediators and autoimmune antibodies, disrupts the serum lipid profile, and thus promotes the progression of AS. In this paper, we summarize the recent evidence (including clinical studies and animal studies) on the correlation between P. gingivalis and AS, and describe the specific immune mechanisms by which P. gingivalis promotes AS progression from three aspects (immune escape, blood circulation, and lymphatic circulation), providing new insights into the prevention and treatment of AS by suppressing periodontal pathogenic bacteria.

Growth Conditions Influence Lactobacillus Cell-Free Supernatant Impact on Viability, Biofilm Formation, and Co-Aggregation of the Oral Periodontopathogens Fusobacterium nucleatum and Porphyromonas gingivalis

Fusobacterium nucleatum and Porphyromonas gingivalis human periodontopathogens play a leading part in oral squamous cell carcinoma through cell proliferation, invasion, and persistent inflammation promotion and maintenance. To explore how the activity of Lactobacillus-derived cell-free supernatants (CFSs) can be influenced by growth medium components, CFSs were produced both in the standard MRS and the novel animal-derivative-free “Terreno Industriale Lattobacilli” (TIL) media, and in vitro screened for the containment of F. nucleatum and P. gingivalis both single and co-cultured and also for the interference on their co-aggregation. The viability assay demonstrated that the Limosilactobacillus reuteri LRE11 and Ligilactobacillus salivarius LS03 MRS-produced CFSs were significantly more effective against single and co-cultured pathogens. All the other CFSs significantly improved their efficacy when produced in TIL. Both MRS- and TIL-produced CFSs significantly inhibited the single and co-cultured pathogen biofilm formation. Only Levilactobacillus brevis LBR01 CFS in MRS specifically reduced F. nucleatum and P. gingivalis co-aggregation, while viable LBR01, LS03, and LRE11 in MRS significantly co-aggregated with the pathogens, but only LS03 cultivated in TIL improved this effect. This work paves the way to better consider environmental growth conditions when screening for probiotic and postbiotic efficacy as crucial to pathogen aggregation, adhesion to the host’s niches, and exclusion.

Aronia melanocarpa (Michx.) Elliott. attenuates dextran sulfate sodium-induced Inflammatory Bowel Disease via regulation of inflammation-related signaling pathways and modulation of the gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Aronia melanocarpa (Michx.) Elliott. Is one of the most functional berries usually used in the preparation of juice and jams, but it has revealed its ethnopharmacological properties due to their richness in biologically active molecules with pharmaceutical and physiological effects.

AIMS OF THE STUDY

The aim of this study was to assess the antioxidant and anti-inflammatory effects of Aronia melanocarpa ethanol-extract as well as the possible mechanisms of action involved and the modulation of gut microbiota in Dextran Sulfate Sodium (DSS)-induced Inflammatory bowel disease in mice.

MATERIALS AND METHODS

Inflammatory bowel disease (IBD) were induced by DSS in drinking water for 7 days to evaluate the properties of A. melanocarpa ethanol-extract (AME) on the intestinal microflora. AME was administered orally to DSS-induced IBD mice for 21 days. Clinical, inflammatory, histopathological parameters, and different mRNA and proteins involved in its possible mechanism of action were determined as well as gut microbiota analysis via 16S high throughput sequencing.

RESULTS

AME improved clinical symptoms and regulated histopathological parameters, pro- and anti-inflammatory cytokines and oxidative stress factors as well as mRNA and protein expressions of transcription factors involved in maintaining the intestinal barrier integrity. In addition, AME also reversed the DSS-induced intestinal dysbiosis effects promoting the production of cecal short chain fatty acids linked to signaling pathways inhibiting IBD.

CONCLUSION

AME improved intestinal lesions induced by DSS suggesting that A. melanocarpa berries could have significant therapeutic potential against IBD due to their antioxidant and anti-inflammatory capacities as well as their ability to restore the gut microbiota balance.

The Protective Effect of Polysaccharide SAFP from Sarcodon aspratus on Water Immersion and Restraint Stress-Induced Gastric Ulcer and Modulatory Effects on Gut Microbiota Dysbiosis

Sarcodon aspratus is a popular edible fungus for its tasty flavour and can be used as a dietary supplement for its functional substances. This study was conducted to evaluate the potential health benefits of Sarcodon aspratus polysaccharides (SAFP) on water immersion and restraint stress (WIRS)-induced gastric ulcer in rats. The results indicated that SAFP could decrease myeloperoxidase (MPO) activity and plasma corticosterone levels, as well as enhance Prostaglandin E2 (PGE2) and Nitrate/nitrite (NOx) concentration in rats. Furthermore, SAFP significantly attenuated the stress damage, inflammation, pathological changes and gastric mucosal lesion in rats. Moreover, high-throughput pyrosequencing of 16S rRNA suggested that SAFP modulated the dysbiosis of gut microbiota by enhancing the relative abundance of probiotics, decreasing WIRS-triggered bacteria proliferation. In summary, these results provided the evidence that SAFP exerted a beneficial effect on a WIRS-induced gastric ulcer via blocking the TLR4 signaling pathway and activating the Nrf2 signaling pathway. Notably, SAFP could modulate the WIRS-induced dysbiosis of gut microbiota. Thus, SAFP might be explored as a natural gastric mucosal protective agent in the prevention of gastric ulcers and other related diseases in the food and pharmaceutical industries.

Interleukin-34 Permits Porphyromonas gingivalis Survival and NF-κB p65 Inhibition in Macrophages

Interleukin-34 (IL-34) is a cytokine that supports the viability and differentiation of macrophages. An important cytokine for the development of epidermal immunity, IL-34 is present and plays a role in the immunity of the oral environment. IL-34 has been linked to inflammatory periodontal diseases, which involve innate phagocytes, including macrophages. Whether IL-34 can alter the ability of macrophages to effectively interact with oral microbes is currently unclear. Using macrophages derived from human blood monocytes with either the canonical cytokine colony-stimulating factor (CSF)1 or IL-34, we compared the ability of the macrophages to phagocytose, kill, and respond through the production of cytokines to the periodontal keystone pathogen Porphyromonas gingivalis. While macrophages derived from both cytokines were able to engulf the bacterium equally, IL-34 derived macrophages were much less capable of killing internalized P. gingivalis. Of the macrophage cell surface receptors known to interact with P. gingivalis, DC-SIGN was found to have the largest variation between IL-34 and CSF1-derived macrophages. We also found that upon interaction with P. gingivalis, IL-34 derived macrophages produced significantly less of the neutrophil chemotactic factor IL-8 than macrophages derived in the presence of CSF1. Mechanistically, we identified that levels of IL-8 corresponded with P. gingivalis survival and dephosphorylation of the major transcription factor NF-κB p65. Overall, we found that macrophages differentiated in the presence of IL-34, a dominant cytokine in the oral gingiva, have a reduced ability to kill the keystone pathogen P. gingivalis and may be susceptible to specific bacteria-mediated cytokine modification. This article is protected by copyright. All rights reserved.

Application Progress of Organoids in Colorectal Cancer

Currently, colorectal cancer is still the third leading cause of cancer-related mortality, and the incidence is rising. It is a long time since the researchers used cancer cell lines and animals as the study subject. However, these models possess various limitations to reflect the cancer progression in the human body. Organoids have more clinical significance than cell lines, and they also bridge the gap between animal models and humans. Patient-derived organoids are three-dimensional cultures that simulate the tumor characteristics in vivo and recapitulate tumor cell heterogeneity. Therefore, the emergence of colorectal cancer organoids provides an unprecedented opportunity for colorectal cancer research. It retains the molecular and cellular composition of the original tumor and has a high degree of homology and complexity with patient tissues. Patient-derived colorectal cancer organoids, as personalized tumor organoids, can more accurately simulate colorectal cancer patients’ occurrence, development, metastasis, and predict drug response in colorectal cancer patients. Colorectal cancer organoids show great potential for application, especially preclinical drug screening and prediction of patient response to selected treatment options. Here, we reviewed the application of colorectal cancer organoids in disease model construction, basic biological research, organoid biobank construction, drug screening and personalized medicine, drug development, drug toxicity and safety, and regenerative medicine. In addition, we also displayed the current limitations and challenges of organoids and discussed the future development direction of organoids in combination with other technologies. Finally, we summarized and analyzed the current clinical trial research of organoids, especially the clinical trials of colorectal cancer organoids. We hoped to lay a solid foundation for organoids used in colorectal cancer research.

Imbalances in TCA, Short Fatty Acids and One-Carbon Metabolisms as Important Features of Homeostatic Disruption Evidenced by a Multi-Omics Integrative Approach of LPS-Induced Chronic Inflammation in Male Wistar Rats

Chronic inflammation is an important risk factor in a broad variety of physical and mental disorders leading to highly prevalent non-communicable diseases (NCDs). However, there is a need for a deeper understanding of this condition and its progression to the disease state. For this reason, it is important to define metabolic pathways and complementary biomarkers associated with homeostatic disruption in chronic inflammation. To achieve that, male Wistar rats were subjected to intraperitoneal and intermittent injections with saline solution or increasing lipopolysaccharide (LPS) concentrations (0.5, 5 and 7.5 mg/kg) thrice a week for 31 days. Biochemical and inflammatory parameters were measured at the end of the study. To assess the omics profile, GC-qTOF and UHPLC-qTOF were performed to evaluate plasma metabolome; 1H-NMR was used to evaluate urine metabolome; additionally, shotgun metagenomics sequencing was carried out to characterize the cecum microbiome. The chronicity of inflammation in the study was evaluated by the monitoring of monocyte chemoattractant protein-1 (MCP-1) during the different weeks of the experimental process. At the end of the study, together with the increased levels of MCP-1, levels of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α) and prostaglandin E2 (PGE2) along with 8-isoprostanes (an indicative of oxidative stress) were significantly increased (p-value < 0.05). The leading features implicated in the current model were tricarboxylic acid (TCA) cycle intermediates (i.e., alpha-ketoglutarate, aconitic acid, malic acid, fumaric acid and succinic acid); lipids such as specific cholesterol esters (ChoEs), lysophospholipids (LPCs) and phosphatidylcholines (PCs); and glycine, as well as N, N-dimethylglycine, which are related to one-carbon (1C) metabolism. These metabolites point towards mitochondrial metabolism through TCA cycle, β-oxidation of fatty acids and 1C metabolism as interconnected pathways that could reveal the metabolic effects of chronic inflammation induced by LPS administration. These results provide deeper knowledge concerning the impact of chronic inflammation on the disruption of metabolic homeostasis.

Diet-Induced Non-alcoholic Fatty Liver Disease and Associated Gut Dysbiosis Are Exacerbated by Oral Infection

Increasing evidence indicates that chronic inflammation due to periodontal disease is associated with progression of non-alcoholic fatty liver disease (NAFLD) caused by a Western diet. NAFLD has also been associated with oral infection with the etiological agent of periodontal disease, Porphyromonas gingivalis. P. gingivalis oral infection has been shown to induce cardiometabolic disease features including hepatic lipid accumulation while also leading to dysbiosis of the gut microbiome. However, the impact of P. gingivalis infection on the gut microbiota of mice with diet-induced NAFLD and the potential for those changes to mediate NAFLD progression has yet to be determined. In the current study, we have demonstrated that P. gingivalis infection induced sustained alterations of the gut microbiota composition and predicted functions, which was associated with the promotion of NAFLD in steatotic mice. Reduced abundance of short-chain fatty acid-producing microbiota was observed after both acute and chronic P. gingivalis infection. Collectively, our findings demonstrate that P. gingivalis infection produces a persistent change in the gut microbiota composition and predicted functions that promotes steatosis and metabolic disease.

Microbiota Emergencies in the Diagnosis of Lung Diseases: A Meta-Analysis

Although many studies have reported that microbiota emergencies are deeply involved in the occurrence and subsequent progression of lung diseases, the present diagnosis of lung disease depends on microbiota markers, which is still poorly understood. Therefore, a meta-analysis was performed to confirm lung microbiota markers for the diagnosis of lung diseases. Literature databases were searched following the inclusion and exclusion criteria. There are 6 studies including 1347 patients and 26 comparisons to be enrolled, and then the diagnostic effect was evaluated using Stata 14.0 and Meta-disc 1.4 software. The pooled sensitivity (SEN), specificity (SPE), diagnostic likelihood ratio positive (DLR+), diagnostic likelihood ratio negative (DLR-), and diagnostic OR (DOR), as well as area under the curve (AUC) of microbiota markers in the diagnosis of lung diseases were 0.90 (95% CI: 0.83-0.94), 0.89 (95% CI: 0.76-0.95), 7.86 (95% CI: 3.39-18.21), 0.12 (95% CI: 0.06-0.21), 22.254 (95% CI: 12.83-39.59.14), and 0.95 (95% CI: 0.93-0.97), respectively. Subgroup analysis revealed that research based on Caucasian, adult, BAL fluid, PCR, pneumonia obtained higher AUC values. The microbiota markers have shown potential diagnosis value for lung diseases. But further large-scale clinical studies are still needed to verify and replicate the diagnostic value of lung microbiota markers.

Inhibition of nuclear factor kappa B inducing kinase suppresses inflammatory responses and the symptoms of chronic periodontitis in a mouse model

Chronic periodontitis is an inflammatory disease that represents a major public health issue nowadays. Here, we investigated the protective role of nuclear factor kappa B (NF-κB) inducing kinase (NIK)-inhibitor on chronic periodontitis and revealed the underlying molecular mechanism. NIK-inhibitor was synthesized, and its functions were examined in primary osteoclasts and wild-type (WT) and NIK-/- chronic periodontitis mouse model. Lipopolysaccharides (LPS) or activator of NF-κB was applied to stimulate inflammatory response of osteoclasts. The qRT-PCR, ELISA and Western blot were used to measure the expression of pro-inflammatory and osteoclast-related genes, and the activation of NF-κB signaling. Osteoclastogenesis and bone damage were detected by TRAP staining and micro-CT. NIK knockdown mice had lower expression of osteoclast-related genes and improved CEJ-ABC damage. Similarly, NIK-inhibitor administration inhibited inflammatory responses and CEJ-ABC damage in chronic periodontitis models. NIK-inhibitor suppressed osteoclastogenesis and osteoclast-related genes expression through inhibiting the non-canonical NF-κB signaling. NIK plays important role in bone destruction of chronic periodontitis and NIK-inhibitor represents a promising therapeutic strategy for this disease.

Impact of calorie restriction and intermittent fasting on periodontal health

The scientific evidence indicates that calorie restriction and intermittent fasting are among the appropriate strategies targeting factual causative factors of various inflammatory and lifestyle-related disorders. Periodontitis is a common oral inflammatory disease leading to bone loss that is associated with various systemic problems. Previous studies suggest that calorie restriction may dampen inflammation and concomitant tissue damage under inflammatory conditions, such as periodontal diseases in nonhuman primates. However, insufficient research has been carried out to assess the effects of a calorie-restricted diet on the initiation and progression of periodontal disease in humans. This review of the literature aims to describe the general concepts of calorie restriction, its clinical implications, and related therapeutic potential in controlling periodontal inflammation. The review shows that fasting regimen groups have shown lesser bone loss because of an increase in osteoprogenitor cells than non-fasting groups. Calorie restriction dampens the inflammatory response and reduces circulating inflammatory mediators like tumor necrosis factor-alpha, interleukin-6, matrix metalloproteinase-8, matrix metalloproteinase-9, and interleukin-1-beta in gingival crevicular fluid. However, the incorporation of this form of dietary intervention continues to be challenging in our current society, in which obesity is a major public concern. Calorie restriction and intermittent fasting can play a key role in the cost-effective resolution of periodontal inflammation as a primary prevention strategy for the management of chronic inflammatory diseases, including periodontal diseases.

Personalized health and the coronavirus vaccines-Do individual genetics matter?

Vaccines represent preventative interventions amenable to immunogenetic prediction of how human variability will influence their safety and efficacy. The genetic polymorphism among individuals within any population can render possible that the immunity elicited by a vaccine is variable in length and strength. The same immune challenge (virus and/or vaccine) could provoke partial, complete or even failed protection for some individuals treated under the same conditions. We review genetic variants and mechanistic relationships among chemokines, chemokine receptors, interleukins, interferons, interferon receptors, toll‐like receptors, histocompatibility antigens, various immunoglobulins and major histocompatibility complex antigens. These are the targets for variation among macrophages, dendritic cells, natural killer cells, T‐ and B‐lymphocytes, and complement. The technology platforms (mRNA, viral vectors, proteins) utilized to produce vaccines against SARS‐CoV‐2 infections may each trigger genetically distinct immune reactogenic profiles. With DNA biobanking and immunoprofiling of recipients, global COVID‐19 vaccinations could launch a new era of personalized healthcare.

Toward improved human health: efficacy of dietary selenium on immunity at the cellular level

Selenium, an essential trace element in the body, participates in various biological processes in the form of selenoproteins. In humans, a suitable concentration of selenium is essential for maintaining normal cellular function. Decreased levels of selenoproteins can lead to obstruction of the normal physiological functions of tissues and cells and even death. In addition, the level of selenium in the body affects cellular immunity, humoral immunity, and the balance between type 2 and type 1 helper T cells. Selenium can affect the immune function of the body through the reactive oxygen species (ROS), NF-κB, ferroptosis and NRF2 pathways. This paper reviews the immune effect of selenium on the body and the process of signal transduction and aims to serve as a reference for follow-up studies of immune function and research on the development of new selenium compounds and active targets.

The Emerging Role of microRNA in Periodontitis: Pathophysiology, Clinical Potential and Future Molecular Perspectives

During the last few decades, it has been established that messenger ribonucleic acid (mRNA) transcription does not inevitably lead to protein translation, but there are numerous processes involved in post-transcriptional regulation, which is a continuously developing field of research. MicroRNAs (miRNAs) are a group of small non-coding RNAs, which negatively regulate protein expression and are implicated in several physiological and pathological mechanisms. Aberrant expression of miRNAs triggers dysregulation of multiple cellular processes involved in innate and adaptive immune responses. For many years, it was thought that miRNAs acted only within the cell in which they were synthesised, but, recently, they have been found outside cells bound to lipids and proteins, or enclosed in extracellular vesicles, namely exosomes. They can circulate throughout the body, transferring information between cells and altering gene expression in the recipient cells, as they can fuse with and be internalised by the recipient cells. Numerous studies on miRNAs have been conducted in order to identify possible biomarkers that can be used in the diagnosis of periodontal disease. However, as therapeutic agents, single miRNAs can target several genes and influence multiple regulatory networks. The aim of this review was to examine the molecular role of miRNAs and exosomes in the pathophysiology of periodontal disease and to evaluate possible clinical and future implications for a personalised therapeutical approach.

Oral Health and Its Aetiological Role in Behçet's Disease

Behçet's disease (BD) is a chronic multi-systemic inflammatory disorder characterised by oro-genital ulcers, cutaneous manifestations, ocular, vascular, neurologic and gastrointestinal involvement. Complex interactions operating on the genetic background e.g.(HLA51), of infectious and other environmental agents, together with immune dysregulation impacts on the pathogenesis of BD. This suggests that the environmental factors triggering immune responses may activate clinical manifestations in genetically susceptible individuals. Since oral health forms the basis of all general health both dental and systemic, it is an important component of both Dentistry and Medicine. Oral ulcers are the most common clinical manifestation of oral mucosal health. Changes in the oral environment consequently acts as an infective and immune trigger. In this review, complex interactions between the oral ulcers, the oral microbiome and immune responses together with the course of oral and systemic disease manifestations in BD are discussed in the context of the aetiologic role of oral health.

Gingival crevicular fluid infiltrating CD14+ monocytes promote inflammation in periodontitis

Periodontitis is a condition that occurs because of inflammation-mediated tissue degeneration. Many studies have been conducted to identify inflammatory molecules in periodontitis, but the well-defined role of cells from the immune system in the progression of periodontitis as well as in gingival tissue degeneration has not been appropriately established. The objective of the present study was to characterize the monocytes isolated from the gingival crevicular fluid (GCF) in patients with periodontitis. GCF was obtained from periodontitis patients and healthy controls. Cytokine levels of CCL2 were evaluated by ELISA in GCF samples. CD14+ monocytes were separated using magnetic sorting from GCF. RT-qPCR was performed to assess the gene expression. Cytometric bead array analysis was performed to analyze the levels of cytokines and chemokines in the secretome of cells. CD14+ monocytes from GCF secreted higher levels of CCL2 and showed elevated expression of genes responsible for monocyte migration. Additionally, upon lipopolysaccharide stimulation, these monocytes secreted higher levels of inflammatory cytokines and chemokines. This investigation aids in understanding the inflammatory microenvironment of periodontitis by characterizing GCF in terms of infiltrated CD14+ monocytes, cytokines, and molecules secreted by these monocytes, which are specific for cellular differentiation.

Role of pulmonary microorganisms in the development of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic obstructive respiratory disease characterized by irreversible airway limitation and persistent respiratory symptoms. The main clinical symptoms of COPD are dyspnoea, chronic cough, and sputum. COPD is often accompanied by other respiratory diseases, which can cause worsening of the disease. COPD patients with dyspnoea and aggravation of cough and sputum symptoms represent acute exacerbations of COPD (AECOPD). There is mounting evidence suggesting that dysbiosis of pulmonary microbiota participates in the disease. However, investigations of dysbiosis of pulmonary microbiota and the disease are still in initial phases. To screen, diagnose, and treat this respiratory disease, integrating data from different studies can improve our understanding of the occurrence and development of COPD and AECOPD. In this review, COPD epidemiology and the primary triggering mechanism are explored. Emerging knowledge regarding the association of inflammation, caused by pulmonary microbiome imbalance, and changes in lung microbiome flora species involved in the development of the disease are also highlighted. These data will further our understanding of the pathogenesis of COPD and AECOPD and may yield novel strategies for the use of pulmonary microbiota as a potential therapeutic intervention.

TAK-242 ameliorates DSS-induced colitis by regulating the gut microbiota and the JAK2/STAT3 signaling pathway

Background

The goal of the present study was to investigate the effects of TAK-242 on the gut microbiota and the TLR4/JAK2/STAT3 signaling pathway in mice with dextran sulfate sodium (DSS)-induced colitis.

Results

At the phylum level, Bacteroidetes, Firmicutes, Actinobacteria, Cyanobacteria, Epsilonbacteraeota and Proteobacteria were the primary microbiota in the five groups. TAK-242 treatment significantly enhanced Verrucomicrobia and Actinobacteria; significantly decreased Cyanobacteria, Epsilonbacteraeota and Proteobacteria; and particularly promoted the growth of Akkermansia. TAK-242 markedly alleviated DSS-induced colitis symptoms and colonic lesions by promoting IL-10 release, inhibiting IL-17 release, downregulating TLR4 and JAK2/STAT3 mRNA and protein expression and increasing JAK2/STAT3 phosphorylation.

Conclusion

TAK-242 modulates the structure of the gut microbiota in colitis and may be a novel therapeutic candidate for ulcerative colitis.

Cross-Sectional Analysis of the Association between Periodontitis and Cardiovascular Disease Using the Korean Genome and Epidemiology Study Data

This cross-sectional study aimed to evaluate the association between periodontitis and cardiovascular disease (CVD) by reviewing and discussing the role of the oral microbiome in periodontitis and CVD. This prospective cohort study used epidemiological data from the Korean Genome and Epidemiology Study from 2004 to 2016. We selected 9973 patients with periodontitis and 125,304 controls (non-periodontitis) from 173,209 participants and analyzed their medical histories to determine the relationship between cerebral stroke/ischemic heart disease and periodontitis. The participants were questioned about any previous history of hypertension, diabetes mellitus, hyperlipidemia, cerebral stroke (hemorrhagic or ischemic), ischemic heart disease (angina or myocardial infarction), and periodontitis. Their body mass index, smoking habit, alcohol intake, nutritional intake, and income were recorded. The Chi-square test, independent t-test, and two-tailed analyses were used for statistical analysis. The adjusted OR (aOR) of periodontitis for stroke was 1.35 (95% confidence interval (CI) = 1.16–1.57, p < 0.001). The aOR of periodontitis for ischemic heart disease was 1.34 (95% CI = 1.22–1.48, p < 0.001). We concluded that periodontitis was associated with CVD and may be a risk factor for CVD. However, further studies are required to determine the association between periodontal treatment and CVD.

Alteration of Fungal Microbiota After 5-ASA Treatment in UC Patients

The effect of treatment regimens on fungal microbiota is unclear in ulcerative colitis (UC) patients. Here, we aimed to clarify the effect of 5-aminosalicylic acid (5-ASA) treatment on gut fungal microbiota in UC patients. Fifty-seven UC patients, including 20 treatment-naïve and 37 5-ASA-treated, were recruited into an exploration study. We compared the gut fungal profiles of these 2 groups of patients using ITS1-2 rDNA sequencing. Ten out of 20 treatment-naïve UC patients were followed up and enrolled for a validation study and underwent a 5-ASA treatment. We assessed the longitudinal differences of fungal microbiota in these patients before and after 5-ASA treatment. Results acquired from the validation study were accordant to those from the exploration study. Ascomycota was the dominant phylum in both noninflamed and inflamed mucosae. At the phylum level, Ascomycota decreased in inflamed mucosae before 5-ASA treatment. At the genus level, pathogens such as Scytalidium, Morchella, and Paecilomyces increased, and Humicola and Wickerhamomyces decreased in inflamed mucosae. After 5-ASA treatment, Ascomycota and Wickerhamomyces increased and Scytalidium, Fusarium, Morchella, and Paecilomyces decreased in both noninflamed and inflamed mucosae. Additionally, the balanced bacteria-fungi correlation was interrupted in inflamed mucosae, and 5-ASA treatment altered group-specific fungal microbiota and restored bacteria-fungi correlation in UC patients. Our results demonstrated that fungal diversity and composition were altered and the bacteria-fungi correlation was restored in inflamed mucosae after 5-ASA treatment.

Interleukin 1β and Prostaglandin E2 affect expression of DNA methylating and demethylating enzymes in human gingival fibroblasts

Periodontitis is a common chronic inflammatory condition that results in increased levels of inflammatory cytokines and inflammatory mediators. In addition to oral disease and tooth loss, it also causes low-grade systemic inflammation that contributes to development of systemic conditions including cardiovascular disease, pre-term birth, diabetes and cancer. Chronic inflammation is associated with epigenetic change, and it has been suggested that such changes can alter cell phenotypes in ways that contribute to both ongoing inflammation and development of associated pathologies. Here we show that exposure of human gingival fibroblasts to IL-1β increases expression of maintenance methyltransferase DNMT1 but decreases expression of de novo methyltransferase DNMT3a and the demethylating enzyme TET1, while exposure to PGE2 decreases expression of all three enzymes. IL-1β and PGE2 both affect global levels of DNA methylation and hydroxymethylation, as well as methylation of some specific CpG in inflammation-associated genes. The effects of IL-1β are independent of its ability to induce production of PGE2, and the effects of PGE2 on DNMT3a expression are mediated by the EP4 receptor. The finding that exposure of fibroblasts to IL-1β and PGE2 can result in altered expression of DNA methylating/demethylating enzymes and in changing patterns of DNA methylation suggests a mechanism through which inflammatory mediators might contribute to the increased risk of carcinogenesis associated with inflammation.

Blockade of Immune-Checkpoint B7-H4 and Lysine Demethylase 5B in Esophageal Squamous Cell Carcinoma Confers Protective Immunity against P. gingivalis Infection

Pathogens are capable of hijacking immune defense mechanisms, thereby creating a tolerogenic environment for hypermutated malignant cells that arise within the site of infection. Immune checkpoint-oriented immunotherapies have shown considerable promise. Equally important, the epigenetic reprogramming of an immune-evasive phenotype that activates the immune system in a synergistic manner can improve immunotherapy outcomes. These advances have led to combinations of epigenetic- and immune-based therapeutics. We previously demonstrated that Porphyromonas gingivalis isolated from esophageal squamous cell carcinoma (ESCC) lesions represents a major pathogen associated with this deadly disease. In this study, we examined the mechanisms associated with host immunity during P. gingivalis infection and demonstrated that experimentally infected ESCC responds by increasing the expression of B7-H4 and lysine demethylase 5B, which allowed subsequent in vivo analysis of the immunotherapeutic effects of anti-B7-H4 and histone demethylase inhibitors in models of chronic infection and immunity against xenografted human tumors. Using three different preclinical mouse models receiving combined therapy, we showed that mice mounted strong resistance against P. gingivalis infection and tumor challenge. This may have occurred via generation of a T cell-mediated response in the microenvironment and formation of immune memory. In ESCC subjects, coexpression of B7-H4 and KDM5B correlated more significantly with bacterial load than with the expression of either molecule alone. These results highlight the unique ability of P. gingivalis to evade immunity and define potential targets that can be exploited therapeutically to improve the control of P. gingivalis infection and the development of associated neoplasia.

Exosome-encapsulated miR-6089 regulates inflammatory response via targeting TLR4

Exosome-encapsulated microRNAs (miRNAs) have been identified as potential biomarkers in autoimmune diseases. However, little is known about the role of exosome-delivered miRNAs in rheumatoid arthritis (RA). In this study, we investigated the profile of specific exosomal miRNAs by microarray analysis of serum exosomes from three patients with RA and three healthy controls. Quantitative real-time PCR (qRT-PCR) was performed to validate the aberrantly expressed exosomal miRNAs. A total of 20 exosome-encapsulated miRNAs were identified to be differently expressed in the serum of patients with RA compared with controls. Interestingly, we found that exosome-encapsulated miR-6089 was significantly decreased after validation by qRT-PCR in serum exosomes from 76 patients with RA and 20 controls. Besides, miR-6089 could inhibit lipopolysaccharide (LPS)-induced cell proliferation and activation of macrophage-like THP-1 cells. TLR4 was a direct target for miR-6089. MiR-6089 regulated the generation of IL-6, IL-29, and TNF-α by targetedly controlling TLR4 signaling. In conclusion, exosome-encapsulated miR-6089 regulates LPS/TLR4-mediated inflammatory response, which may serve as a novel, promising biomarker in RA.

Dysregulation of miR-146a by periodontal pathogens: A risk for acute coronary syndrome

BACKGROUND

Periodontitis is a polymicrobial, chronic inflammatory disease leading to loss of tooth-supporting structures. The bacteremia, endotoxemia, and systemic low-grade inflammation associate periodontitis with systemic illnesses such as diabetes mellitus and coronary artery disease. Periodontal pathogens have been detected from atheromatous plaque by amplification of the genetic material by using specific oligonucleotide primers in polymerase chain reaction. Though the association between periodontitis and cardiovascular diseases has been ascertained by systematic reviews and meta-analyses, its pathophysiology is not lucid. MicroRNAs are currently implicated in the regulation of many cellular processes including inflammation and may play a vital role in our understanding of this disease association. In this case-control study, we explored the role of the inflammatory microRNA, miR-146a, in acute coronary syndrome (ACS) subjects with and without chronic periodontitis (CP) and its regulation of the innate immune host response to periodontal pathogens.

METHODS

Three groups each comprising 66 patients each, namely group 1 (ACS patients without CP), group 2 (ACS patients with CP) and group 3 (CP only) formed the study population. Subgingival plaque samples and serum samples were subjected to quantitative Polymerase Chain Reaction (qPCR) for detection of Porphyromonas gingivalis, a keystone pathogen and to assess the levels of circulating miR-146a and associated proinflammatory cytokines.

RESULTS

miR-146a associated significantly in group 2 subjects with an odds ratio 1.434, 95% confidence interval 1.013-2.030, P < 0.042, and a predictive percentage of 83.3% and group 1 with a predictive percentage of 76.0.% The associated cytokines interleukin-6 (IL-6), tumor necrosis factor-α, and IL-1β also showed an upregulation with statistical significance (P < 0.05).

CONCLUSION

microRNA-146a is a key molecule associating periodontitis with acute coronary syndrome.

A randomised trial of probiotics to reduce severity of physiological and microbial disorders induced by partial gastrectomy for patients with gastric cancer

Gastrectomy has been widely used for the treatment of gastric cancer, and the severity of physiological and microbial disorders has greatly harmed the health of patients. In the present study, a probiotic combination containing Bifidobacterium infantis, Lactobacillus acidophilus, Enterococcus faecalis and Bacillus cereus was used to reduce the physiological disorders induced by gastrectomy via monitoring the blood index and microbial diversity using high-throughput sequencing. Our results indicated that the probiotic combination had significantly reduced the inflammation indexes (leukocyte) (p<0.05), while it markedly enhanced the immunity indexes (lymphocyte) and nutrition indexes (albumin and total protein) (p<0.05). In addition, gastric cancer had a strong influence on the microbial diversity of the stomach via enhancing the number of pathogens of Streptococcus, Peptostreptococcus and Prevotella, and reducing the percentage of the probiotic Bifidobacterium. Although partial gastrectomy markedly changed intestinal microbial diversity, the taking of the probiotic combination greatly reduced the ratio of Firmicutes/Bacteroidetes compared with patients taking no probiotics at the phylum level. At the genus level, the probiotic combination significantly enhanced the numbers of the probiotic bacteria Bacteroides, Faecalibacterium and Akkermansia and lowered the richness of Streptococcus. Therefore, we concluded that the taking of the probiotic combination significantly enhances the immune response of patients and reduces the severity of inflammation through modification of gut microbiota.

Subgingival lipid A profile and endotoxin activity in periodontal health and disease

OBJECTIVES

Regulation of lipopolysaccharide (LPS) chemical composition, particularly its lipid A domain, is an important, naturally occurring mechanism that drives bacteria-host immune system interactions into either a symbiotic or pathogenic relationship. Members of the subgingival oral microbiota can critically modulate host immuno-inflammatory responses by synthesizing different LPS isoforms. The objectives of this study were to analyze subgingival lipid A profiles and endotoxin activities in periodontal health and disease and to evaluate the use of the recombinant factor C assay as a new, lipid A-based biosensor for personalized, point-of-care periodontal therapy.

MATERIALS AND METHODS

Subgingival plaque samples were collected from healthy individuals and chronic periodontitis patients before and after periodontal therapy. Chemical composition of subgingival lipid A moieties was determined by ESI-Mass Spectrometry. Endotoxin activity of subgingival LPS extracts was assessed using the recombinant factor C assay, and their inflammatory potential was examined in THP-1-derived macrophages by measuring TNF-α and IL-8 production.

RESULTS

Characteristic lipid A molecular signatures, corresponding to over-acylated, bi-phosphorylated lipid A isoforms, were observed in diseased samples. Healthy and post-treatment samples were characterized by lower m/z peaks, related to under-acylated, hypo-phosphorylated lipid A structures. Endotoxin activity levels and inflammatory potentials of subgingival LPS extracts from periodontitis patients were significantly higher compared to healthy and post-treatment samples.

CONCLUSIONS

This is the first study to consider structure-function-clinical implications of different lipid A isoforms present in the subgingival niche and sheds new light on molecular pathogenic mechanisms of subgingival biofilm communities.

CLINICAL RELEVANCE

Subgingival endotoxin activity (determined by lipid A chemical composition) could be a reliable, bacterially derived biomarker and a risk assessment tool for personalized periodontal care.

A systematic review and critical evaluation of inflammatory cytokine associations in hidradenitis suppurativa

Background: The pathogenesis of hidradenitis suppurativa (HS) remains unclear. In order to develop effective treatment strategies, a deeper understanding of pathophysiology is needed. This is impaired by multiple small studies with inconsistent methodologies and the impact of co-occurring pro-inflammatory conditions such as smoking and obesity.

Methods: This systematic review aimed to collate all published reports of cytokine studies in tissue, blood, serum and exudate. It was registered with PROSPERO (Registration number CRD42018104664) performed in line with the PRISMA checklist.

Results: 19 studies were identified comprising 564 individual HS patients and 198 control patients examining 81 discrete cytokines. Methodology was highly varied and the quality of studies was generally low. There was a large degree of variance between the measured levels of cytokines. 78.2% of cytokines demonstrated heterogeneity by the chi-squared test for homogeneity and hence meta-analysis was not deemed appropriate. However, a strong and significant IL-17 signalling component was identified.

Conclusions: Cytokines consistently elevated in lesional, peri-lesional and unaffected tissue are identified and discussed. Areas for further investigation include the role of dendritic cells in HS; the contribution of obesity, smoking, diabetes and the microbiome to cytokine profiles in HS; and examining the natural history of this disease through longitudinal measurements of cytokines over time.

Gut microbes as future therapeutics in treating inflammatory and infectious diseases: Lessons from recent findings

The human gut microbiota has been the interest of extensive research in recent years and our knowledge on using the potential capacity of these microbes are growing rapidly. Microorganisms colonized throughout the gastrointestinal tract of human are coevolved through symbiotic relationship and can influence physiology, metabolism, nutrition and immune functions of an individual. The gut microbes are directly involved in conferring protection against pathogen colonization by inducing direct killing, competing with nutrients and enhancing the response of the gut-associated immune repertoire. Damage in the microbiome (dysbiosis) is linked with several life-threatening outcomes viz. inflammatory bowel disease, cancer, obesity, allergy, and auto-immune disorders. Therefore, the manipulation of human gut microbiota came out as a potential choice for therapeutic intervention of the several human diseases. Herein, we review significant studies emphasizing the influence of the gut microbiota on the regulation of host responses in combating infectious and inflammatory diseases alongside describing the promises of gut microbes as future therapeutics.

Screening of herbal extracts for TLR2- and TLR4-dependent anti-inflammatory effects

Herbal extracts represent an ample source of natural compounds, with potential to be used in improving human health. There is a growing interest in using natural extracts as possible new treatment strategies for inflammatory diseases. We therefore aimed at identifying herbal extracts that affect inflammatory signaling pathways through toll-like receptors (TLRs), TLR2 and TLR4. Ninety-nine ethanolic extracts were screened in THP-1 monocytes and HeLa-TLR4 transfected reporter cells for their effects on stimulated TLR2 and TLR4 signaling pathways. The 28 identified anti-inflammatory extracts were tested in comparative assays of stimulated HEK-TLR2 and HEK-TLR4 transfected reporter cells to differentiate between direct TLR4 antagonistic effects and interference with downstream signaling cascades. Furthermore, the ten most effective anti-inflammatory extracts were tested on their ability to inhibit nuclear factor-κB (NF-κB) translocation in HeLa-TLR4 transfected reporter cell lines and for their ability to repolarize M1-type macrophages. Ethanolic extracts which showed the highest anti-inflammatory potential, up to a complete inhibition of pro-inflammatory cytokine production were Castanea sativa leaves, Cinchona pubescens bark, Cinnamomum verum bark, Salix alba bark, Rheum palmatum root, Alchemilla vulgaris plant, Humulus lupulus cones, Vaccinium myrtillus berries, Curcuma longa root and Arctostaphylos uva-ursi leaves. Moreover, all tested extracts mitigated not only TLR4, but also TLR2 signaling pathways. Seven of them additionally inhibited translocation of NF-κB into the nucleus. Two of the extracts showed impact on repolarization of pro-inflammatory M1-type to anti-inflammatory M2-type macrophages. Several promising anti-inflammatory herbal extracts were identified in this study, including extracts with previously unknown influence on key TLR signaling pathways and macrophage repolarization, serving as a basis for novel lead compound identification.

5-Aminosalicylic Acid Alters the Gut Bacterial Microbiota in Patients With Ulcerative Colitis

Background: The aim of this study was to clarify the effect of 5-aminosalicylic acid (5-ASA) treatment on gut bacterial microbiota in patients with ulcerative colitis (UC).

Methods: A total of 57 UC patients, including 20 untreated and 37 5-ASA-treated, were recruited into an exploration cohort. We endoscopically collected both non-inflamed and inflamed mucosal samples from all patients, and compared the gut bacterial profiles using 16S rDNA sequencing. Ten untreated UC patients were then treated with 5-ASA and subsequently recruited for an independent validation study to confirm the acquired data.

Results: In untreated UC patients, compared with those in non-inflamed mucosae, Firmicutes (such as Enterococcus) were decreased and Proteobacteria (e.g., Escherichia–Shigella) were increased in the inflamed mucosae. Compared with the inflamed mucosae of untreated UC patients, there was a higher abundance of Firmicutes (e.g., Enterococcus) and lower Proteobacteria (Escherichia–Shigella) in the inflamed mucosae of 5-ASA treated UC patients. In the validation cohort, after administration of 5-ASA, bacterial alteration was consistent with these data. Furthermore, there was a skewed negative correlation between Escherichia–Shigella and bacterial genera of Firmicutes in the inflamed mucosae. 5-ASA treatment decreased the strength of bacterial correlation and weakened the skewed negative correlation pattern.

Conclusion: The microbial dysbiosis (mainly characterized by an increased abundance in the Escherichia–Shigella genus) and the skewed negative correlation between Escherichia–Shigella and bacterial genera of Firmicutes are two characteristics of the inflamed mucosae of UC patients. 5-ASA treatment decreases Escherichia–Shigella and weakens the skewed correlations, which may be related to its treatment efficiency.

Bacteriophages targeting intestinal epithelial cells: a potential novel form of immunotherapy

In addition to their established role as a physical barrier to invading pathogens and other harmful agents, intestinal epithelial cells (IEC) are actively involved in local immune reactions. In the past years, evidence has accumulated suggesting the role of IEC in the immunopathology of intestinal inflammatory disorders (IBD). Recent advances in research on bacteriophages strongly suggest that-in addition to their established antibacterial activity-they have immunomodulating properties that are potentially useful in the clinic. We suggest that these immunomodulating phage activities targeting IEC may open novel treatment perspectives in disorders of the alimentary tract, particularly IBD.

Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders

Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.

Updating osteoimmunology: regulation of bone cells by innate and adaptive immunity

Osteoimmunology encompasses all aspects of the cross-regulation of bone and the immune system, including various cell types, signalling pathways, cytokines and chemokines, under both homeostatic and pathogenic conditions. A number of key areas are of increasing interest and relevance to osteoimmunology researchers. Although rheumatoid arthritis has long been recognized as one of the most common autoimmune diseases to affect bone integrity, researchers have focused increased attention on understanding how molecular triggers and innate signalling pathways (such as Toll-like receptors and purinergic signalling pathways) related to pathogenic and/or commensal microbiota are relevant to bone biology and rheumatic diseases. Additionally, although most discussions relating to osteoimmune regulation of homeostasis and disease have focused on the effects of adaptive immune responses on bone, evidence exists of the regulation of immune cells by bone cells, a concept that is consistent with the established role of the bone marrow in the development and homeostasis of the immune system. The active regulation of immune cells by bone cells is an interesting emerging component of investigations that seek to understand how to control immune-associated diseases of the bone and joints.

NLRP3 inflammasome pathways in atherosclerosis

Atherosclerosis is the major cause of death and disability. Atherosclerotic plaques are characterized by a chronic sterile inflammation in the large blood vessels, where lipid-derived and damage-associated molecular patterns play important roles in inciting immune responses. Following the initial demonstration that NLR family Pyrin domain containing 3 (NLRP3) was important for atherogenesis, a substantial number of studies have emerged addressing the basic mechanisms of inflammasome activation and their relevance to atherosclerosis. In this review, we introduce the basic cellular and molecular mechanisms of NLRP3 inflammasome activation, and discuss the current findings and therapeutic strategies that target NLRP3 inflammasome activation during the development and progression of atherosclerosis.

Maternal modifiers of the infant gut microbiota: metabolic consequences

Transmission of metabolic diseases from mother to child is multifactorial and includes genetic, epigenetic and environmental influences. Evidence in rodents, humans and non-human primates support the scientific premise that exposure to maternal obesity or high-fat diet during pregnancy creates a long-lasting metabolic signature on the infant innate immune system and the juvenile microbiota, which predisposes the offspring to obesity and metabolic diseases. In neonates, gastrointestinal microbes introduced through the mother are noted for their ability to serve as direct inducers/regulators of the infant immune system. Neonates have a limited capacity to initiate an immune response. Thus, disruption of microbial colonization during the early neonatal period results in disrupted postnatal immune responses that highlight the neonatal period as a critical developmental window. Although the mechanisms are poorly understood, increasing evidence suggests that maternal obesity or poor diet influences the development and modulation of the infant liver and other end organs through direct communication via the portal system, metabolite production, alterations in gut barrier integrity and the hematopoietic immune cell axis. This review will focus on how maternal obesity and dietary intake influence the composition of the infant gut microbiota and how an imbalance or maladaptation in the microbiota, including changes in early pioneering microbes, might contribute to the programming of offspring metabolism with special emphasis on mechanisms that promote chronic inflammation in the liver. Comprehension of these pathways and mechanisms will elucidate our understanding of developmental programming and may expand the avenue of opportunities for novel therapeutics.

Faecal and mucosal microbiota in patients with functional gastrointestinal disorders: Correlation with toll-like receptor 2/toll-like receptor 4 expression

AIM

To investigate the intestinal luminal microbiota (LM) and mucosa-associated microbiota (MAM) in Chinese patients with functional gastrointestinal disorders (FGIDs) and examine the association between these communities and the expression of toll-like receptor (TLR) 2 and TLR4.

METHODS

Thirty-two Chinese subjects who suffered from symptoms of FGIDs, as confirmed by gastroenterologists, were enrolled in this study. Fresh faecal samples and descending colonic mucosal biopsies were collected from the subjects before (faecal) and during (mucosal) flexible colonoscopy. For analysis of the samples, we performed high-throughput sequencing of the V3-V4 region of the 16S rRNA gene and reverse transcription (RT)-PCR to detect the expression of colonic TLR2 and TLR4. Differences in the stool and mucosal microbiota were examined and a correlation network analysis was performed.

RESULTS

The microbiota of faecal samples was significantly more diverse and richer than that of the mucosal samples, and the LM and MAM populations differed significantly. TLR2 expression showed a significant positive correlation with TLR4 expression. In the MAM samples, the genera Faecalibacterium and Ruminococcus, which belong to the family Ruminococcaceae, were inversely correlated with TLR4 expression (r = -0.45817, P = 0.0083 and r = -0.5306, P = 0.0018, respectively). Granulicatella, which belongs to Carnobacteriaceae, and Streptococcus, which belongs to Streptococcaceae, were inversely correlated with TLR2 expression (r = -0.5573, P = 0.0010 and r = -0.5435, P = 0.0013, respectively). In the LM samples, examination at phylum, class, or order level revealed no correlation with TLR4 expression. Faecalibacterium, which belongs to Ruminococcaceae, and Streptococcus, which belongs to Streptococcaceae, were inversely correlated with TLR2 expression (r = -0.5743, P = 0.0058 and r = -0.3905, P = 0.0271, respectively).

CONCLUSION

Microbial compositions of LM and MAM in Chinese patients with FGIDs are different. Expression of TLRs may be affected by the type of bacteria that are present in the gut.

Adjuvanting an inactivated influenza vaccine with conjugated R848 improves the level of antibody present at 6months in a nonhuman primate neonate model

Generation of a potent antibody response that can be sustained over time is highly challenging in young infants. Our previous studies using a nursery-reared nonhuman primate model identified R848 conjugated to inactivated influenza virus as a highly immunogenic vaccine for neonates. Here we determined the effectiveness of this vaccine in mother-reared infants as well as its ability to promote improved responses at 6months compared to vaccination in the absence of R848. In agreement with our nursery study, R848 conjugated to influenza virus induced a higher antibody response in neonates compared to the non-adjuvanted vaccine. Further, the increase in the response relative to that induced by the non-adjuvanted vaccine was maintained at 6months suggesting the increased antibody secreting cells that resulted from inclusion of conjugated R848 production were capable of surviving long term. There was no significant difference in quality of antibody (i.e. neutralization or affinity), suggesting the beneficial effect of conjugated R848 during vaccination of neonates with inactivated influenza virus is likely manifest during the early generation of antibody secreting cells.