Role of human microbiome and selected bacterial infections in the pathogenesis of rheumatoid arthritis

Moderate-intensity continuous training and high-intensity interval training modulate the composition of the oral microbiota of elderly adults: Randomized controlled trial

OBJECTIVE

We investigates the effects of 16-week high-intensity interval training and moderate-intensity continuous training on the composition of the oral microbiota. To the best of our knowledge, at the time of writing this paper no other scholars had described the oral metagenomic changes associated with prescribed exercise in older adults.

METHODS

Forty-three participants aged 60-74 years were randomized 1:1:1 to a control group, high-intensity interval training or moderate-intensity continuous training twice weekly for 16 weeks. Saliva samples were sequenced at baseline, week 8 and week 16 of intervention.

RESULTS

High-intensity interval training produced significant differences over time in Richness and a clear trend to decreased Simpson and Shannon diversity indices. In contrast, Simpson and Shannon indices showed an upward trend over time with moderate-intensity continuous training, which also decreased Firmicutes and increased Bacteroidetes levels. Significant differences in the abundance of pathogenic species were also observed after the participants completed the exercise interventions of either type.

CONCLUSIONS

Both types of exercise promoted subtle changes in the oral microbiota, confirming the modulatory effect of high-intensity interval training and moderate-intensity continuous training on the oral microbiome. Clinical trial registration NCT05220670.

Oral microbiota-host interaction: the chief culprit of alveolar bone resorption

There exists a bidirectional relationship between oral health and general well-being, with an imbalance in oral symbiotic flora posing a threat to overall human health. Disruptions in the commensal flora can lead to oral diseases, while systemic illnesses can also impact the oral cavity, resulting in the development of oral diseases and disorders. Porphyromonas gingivalis and Fusobacterium nucleatum, known as pathogenic bacteria associated with periodontitis, play a crucial role in linking periodontitis to accompanying systemic diseases. In periodontal tissues, these bacteria, along with their virulence factors, can excessively activate the host immune system through local diffusion, lymphatic circulation, and blood transmission. This immune response disruption contributes to an imbalance in osteoimmune mechanisms, alveolar bone resorption, and potential systemic inflammation. To restore local homeostasis, a deeper understanding of microbiota-host interactions and the immune network phenotype in local tissues is imperative. Defining the immune network phenotype in periodontal tissues offers a promising avenue for investigating the complex characteristics of oral plaque biofilms and exploring the potential relationship between periodontitis and associated systemic diseases. This review aims to provide an overview of the mechanisms underlying Porphyromonas gingivalis- and Fusobacterium nucleatum-induced alveolar bone resorption, as well as the immunophenotypes observed in host periodontal tissues during pathological conditions.

Exploring the Role of IL-17A in Oral Dysbiosis-Associated Periodontitis and Its Correlation with Systemic Inflammatory Disease

Oral microbiota play a pivotal role in maintaining homeostasis, safeguarding the oral cavity, and preventing the onset of disease. Oral dysbiosis has the potential to trigger pro-inflammatory effects and immune dysregulation, which can have a negative impact on systemic health. It is regarded as a key etiological factor for periodontitis. The emergence and persistence of oral dysbiosis have been demonstrated to mediate inflammatory pathology locally and at distant sites. The heightened inflammation observed in oral dysbiosis is dependent upon the secretion of interleukin-17A (IL-17A) by various innate and adaptive immune cells. IL-17A has been found to play a significant role in host defense mechanisms by inducing antibacterial peptides, recruiting neutrophils, and promoting local inflammation via cytokines and chemokines. This review seeks to present the current knowledge on oral dysbiosis and its prevention, as well as the underlying role of IL-17A in periodontitis induced by oral dysbiosis and its impact on systemic inflammatory disease.

Mitogen-Activated Protein Kinases (MAPKs) and Enteric Bacterial Pathogens: A Complex Interplay

Diverse extracellular and intracellular cues activate mammalian mitogen-activated protein kinases (MAPKs). Canonically, the activation starts at cell surface receptors and continues via intracellular MAPK components, acting in the host cell nucleus as activators of transcriptional programs to regulate various cellular activities, including proinflammatory responses against bacterial pathogens. For instance, binding host pattern recognition receptors (PRRs) on the surface of intestinal epithelial cells to bacterial pathogen external components trigger the MAPK/NF-κB signaling cascade, eliciting cytokine production. This results in an innate immune response that can eliminate the bacterial pathogen. However, enteric bacterial pathogens evolved sophisticated mechanisms that interfere with such a response by delivering virulent proteins, termed effectors, and toxins into the host cells. These proteins act in numerous ways to inactivate or activate critical components of the MAPK signaling cascades and innate immunity. The consequence of such activities could lead to successful bacterial colonization, dissemination, and pathogenicity. This article will review enteric bacterial pathogens' strategies to modulate MAPKs and host responses. It will also discuss findings attempting to develop anti-microbial treatments by targeting MAPKs.

Elevated dietary carbohydrate and glycemic intake associate with an altered oral microbial ecosystem in two large U.S. cohorts

The human oral microbiome is associated with chronic diseases including cancer. However, our understanding of its relationship with diet is limited. We assessed the associations between carbohydrate and glycemic index (GI) with oral microbiome composition in 834 non-diabetic subjects from the NCI-PLCO and ACS-CPSII cohorts. The oral microbiome was characterized using 16Sv3-4 rRNA-sequencing from oral mouthwash samples. Daily carbohydrate and GI were assessed from food frequency questionnaires. We used linear regression, permutational MANOVA, and negative binomial Generalized Linear Models (GLM) to test associations of diet with α- and β-diversity and taxon abundance (adjusting for age, sex, cohort, BMI, smoking, caloric intake, and alcohol). A q-value (FDR-adjusted P-value) of <0.05 was considered significant. Oral bacterial α-diversity trended higher in participants in the highest quintiles of carbohydrate intake, with marginally increased richness and Shannon diversity (p-trend=0.06 and 0.07). Greater carbohydrate intake was associated with greater abundance of class Fusobacteriia (q=0.02) and genus Leptotrichia (q=0.01) and with lesser abundance of an Actinomyces OTU (q=4.7E-04). Higher GI was significantly related to greater abundance of genus Gemella (q=0.001). This large, nationwide study provides evidence that diets high in carbohydrates and GI may influence the oral microbiome.

Biomolecular Mechanisms of Autoimmune Diseases and Their Relationship with the Resident Microbiota: Friend or Foe?

The use of innovative approaches to elucidate the pathophysiological mechanisms of autoimmune diseases, as well as to further study of the factors which can have either a positive or negative effect on the course of the disease, is essential. In this line, the development of new molecular techniques and the creation of the Human Genome Program have allowed access to many more solutions to the difficulties that exist in the identification and characterization of the microbiome, as well as changes due to various factors. Such innovative technologies can rekindle older hypotheses, such as molecular mimicry, allowing us to move from hypothesis to theory and from correlation to causality, particularly regarding autoimmune diseases and dysbiosis of the microbiota. For example, Prevotella copri appears to have a strong association with rheumatoid arthritis; it is expected that this will be confirmed by several scientists, which, in turn, will make it possible to identify other mechanisms that may contribute to the pathophysiology of the disease. This article seeks to identify new clues regarding similar correlations between autoimmune activity and the human microbiota, particularly in relation to qualitative and quantitative microbial variations therein.

Pyropia yezoensis porphyran alleviates metabolic disorders via modulating gut microbiota in high-sucrose-fed Drosophila melanogaster

BACKGROUND

Prebiotics, such as algal polysaccharides, can be used to manage metabolic diseases by modulating gut microbiota. However, the effect of Pyropia yezoensis porphyran (PYP), a red algal polysaccharide, on gut microbiota has not been reported. Thus, the objective of this study was to determine effects of PYP on metabolic disorders caused by high sucrose (HS) and underlying mechanisms involved in such effects.

RESULTS

Biochemical analysis demonstrated that an HS diet increased triglyceride and circulating sugar contents (metabolic abnormalities) in Drosophila larvae. It also increased the relative abundance of harmful microbiota within the larvae as identified by 16S ribosomal DNA analysis. PYP supplementation at 25 and 50 g kg^-1 equivalently reduced metabolic abnormalities in the HS group. Therefore, 25 g kg^-1 PYP was selected to investigate its effects on the metabolic pathway and gut microbiota of larvae in the HS group. The activity of PYP in ameliorating metabolic abnormalities by reverse transcription quantitative real-time polymerase chain reaction analysis was consistent with the expression trend of key factors involved in metabolism regulation. PYP reduced the relative abundance of bacteria causing metabolic abnormalities, such as Escherichia-Shigella and Fusobacterium, but increased the relative abundance of beneficial bacteria such as Bacillus and Akkermansia. However, PYP had no effect on triglyceride and circulating sugar contents in HS-fed larvae treated with a mixture of antibiotics designed to remove gut microbiota.

CONCLUSION

PYP exhibits anti-metabolic disorder activity by modulating gut microbiota, thereby supporting the development of PYP as a functional prebiotic derived from red algae food. Copyright © 2022 John Wiley & Sons, Ltd. © 2022 Society of Chemical Industry.

A Clinical Study on the Relationship Among Insomnia, Tongue Diagnosis, and Oral Microbiome

Currently, there is a lack of adequate methods to assess insomnia objectively. This study addresses the usefulness of tongue features and oral microbial profile as a potential diagnostic biomarker of insomnia. One hundred insomniac patients and 20 healthy control subjects were selected. Their demographic and clinical characteristics, as well as the tongue diagnostic indices and oral microbial profile, were examined. Compared to the control group, insomniac patients showed a higher abnormal low-frequency/high-frequency (LF/HF) ratio. In tongue diagnosis, the indices related to lightness of tongue body and tongue coating were higher in the insomniac group vs. the control group. Furthermore, linear discriminant analysis (LDA) of oral microbial population revealed that the relative abundances of Clostridia, Veillonella, Bacillus and Lachnospiraceae were significantly higher in the insomniac patients than the control group. Additionally, the tongue features of the insomniac group exhibited that the non-coating group had a poor sleep condition compared to the thick-coating group, although the difference was insignificant. On the other hand, the oral microbial communities of the insomniac patients revealed greater alpha and beta diversities in the non-coating group vs. the thick-coating group. The alpha and beta diversities were higher in orotype1 than orotype2. Collectively, this study highlighted that the lightness of tongue body and tongue coating as well as oral microbial profiles of SR1, Actinobacteria, Clostridia and Lachnospiraceae_unclassified could be considered potential biomarkers of insomnia.

Phytochemicals From Vicia faba Beans as Ligands of the Aryl Hydrocarbon Receptor to Regulate Autoimmune Diseases

Legumes are associated with gut health benefits, and increasing evidence indicates that their consumption reduces the risk of chronic diseases that include autoimmunity. Beans are rich sources of compounds with health-promoting effects, and recent metabolomic approaches have enabled the comprehensive characterization of the chemical composition of Vicia faba L. This article reviewed whether the phytocompounds in broad beans might modulate the aryl hydrocarbon receptor (AhR), which plays an essential role in autoantigen tolerance as a potential dietary strategy for autoimmune disease management. Therefore, thirty molecules present in Vicia faba of the chemical classes of flavonoids, chalcones, stilbenes, jasmonates, alkaloids, and amino acids, and either a human- or microbiome-derived product of biotransformation, retrieved from the literature or predicted in silico were evaluated by docking for affinity against the ligand-binding domain of AhR. Most analyzed compounds showed high affinity even after their metabolism which indicate that some AhR modulators remain active despite several steps in their biotransformation. Hence, our results suggest that in similitude with the gut metabolism of the tryptophan, phytocompounds mainly polyphenols also lead to metabolites that induce the AhR pathway. Furthermore, wyerone acid, wyerone epoxide, jasmonic acid, stizolamine, vicine, and convicine and their metabolite derivatives are reported for the first time as potential AhR ligands. Overall, chronic consumption of phytochemicals in Vicia faba L. and their gut biotransformation may protect against autoimmune disease pathogenesis by AhR modulation.

Armed to the Teeth-The Oral Mucosa Immunity System and Microbiota

The oral cavity is inhabited by a wide spectrum of microbial species, and their colonization is mostly based on commensalism. These microbes are part of the normal oral flora, but there are also opportunistic species that can cause oral and systemic diseases. Although there is a strong exposure to various microorganisms, the oral mucosa reduces the colonization of microorganisms with high rotation and secretion of various types of cytokines and antimicrobial proteins such as defensins. In some circumstances, the imbalance between normal oral flora and pathogenic flora may lead to a change in the ratio of commensalism to parasitism. Healthy oral mucosa has many important functions. Thanks to its integrity, it is impermeable to most microorganisms and constitutes a mechanical barrier against their penetration into tissues. Our study aims to present the role and composition of the oral cavity microbiota as well as defense mechanisms within the oral mucosa which allow for maintaining a balance between such numerous species of microorganisms. We highlight the specific aspects of the oral mucosa protecting barrier and discuss up-to-date information on the immune cell system that ensures microbiota balance. This study presents the latest data on specific tissue stimuli in the regulation of the immune system with particular emphasis on the resistance of the gingival barrier. Despite advances in understanding the mechanisms regulating the balance on the microorganism/host axis, more research is still needed on how the combination of these diverse signals is involved in the regulation of immunity at the oral mucosa barrier.

Exploring the Oral Microbiome in Rheumatic Diseases, State of Art and Future Prospective in Personalized Medicine with an AI Approach

The oral microbiome is receiving growing interest from the scientific community, as the mouth is the gateway for numerous potential etiopathogenetic factors in different diseases. In addition, the progression of niches from the mouth to the gut, defined as "oral-gut microbiome axis", affects several pathologies, as rheumatic diseases. Notably, rheumatic disorders (RDs) are conditions causing chronic, often intermittent pain affecting the joints or connective tissue. In this review, we examine evidence which supports a role for the oral microbiome in the etiology and progression of various RDs, including rheumatoid arthritis (RA), Sjogren's syndrome (SS), and systemic lupus erythematosus (SLE). In addition, we address the most recent studies endorsing the oral microbiome as promising diagnostic biomarkers for RDs. Lastly, we introduce the concepts of artificial intelligence (AI), in particular, machine learning (ML) and their general application for understanding the link between oral microbiota and rheumatic diseases, speculating the application of a possible AI approach-based that can be applied to personalized medicine in the future.

Rheumatoid arthritis risk in periodontitis patients: A systematic review and meta-analysis

OBJECTIVE

Many clinical studies have been carried out to investigate the relationship between periodontitis and rheumatoid arthritis (RA). Owing to limited evidence and inconsistent findings among these studies, it is unclear whether periodontitis would increase the risk for RA. This meta-analysis was performed to evaluate whether periodontitis represents a risk factor for RA.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, and Wanfang were searched for eligible studies that compared periodontitis patients with controls. A pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association between periodontitis and RA.

RESULTS

Thirteen studies including a total of 706611 periodontitis patients and 349983 control subjects were included. The pooled OR of RA risk between periodontitis and controls was (OR: 1.69; 95% CI: 1.31-2.17; P<0.0001), indicating that the patients in periodontitis group had a 69% greater risk for RA than people in control group. When stratified by disease type, the pooled results showed periodontitis represents a risk factor for incident RA (OR=1.70, 95%CI: 0.75-3.85, P<0.001) and mixed RA (OR=1.61, 95%CI: 1.26-2.06; P<0.001). When stratified by disease duration, the pooled results showed periodontitis represents a risk factor for RA disease duration>5 years (OR=2.88, 95%CI: 0.66-12.62, P=0.018), disease duration<5 years (OR=2.59, 95%CI: 0.83-8.11, P<0.001), mixed disease duration (OR=1.53; 95%CI: 1.05-2.22, P<0.001).

CONCLUSION

Our meta-analysis revealed an increased risk of RA in patients with periodontitis compared to healthy controls. Moreover, when stratified by disease type, there was a higher risk between incident RA and periodontitis. When stratified by disease duration, the patients with periodontitis might be more closely associated with the RA patients with disease duration >5 years.

Microbiome and autoimmune diseases: cause and effect relationship

PURPOSE OF REVIEW

The human body is the host of trillions of different prokaryotic microorganisms that colonize the skin and the mucosae. The interaction between human cells and these organisms is mediated by the immune system, sustaining a very complex and fragile balance. The immune cells need to prevent uncontrolled growth of pathogenic microbes and promote tolerance toward the existence of the beneficial ones. Growing evidence associates the disruption of this symbiotic relationship with the development of autoimmune diseases.

RECENT FINDINGS

Human studies led to the identification of gut dysbiosis patterns in patients with rheumatoid arthritis, lupus and multiple sclerosis. Interestingly, the inoculation of pathogenic bacteria in animal models was associated with the development of these autoimmune diseases.

SUMMARY

A better understanding of the microbiota-human interaction will enable the development of novel treatment choices. Currently, new molecules using helminth compounds are under investigation and have already revealed promising results.

The Human Oral Microbiome in Health and Disease: From Sequences to Ecosystems

Abstract: The human oral cavity is home to an abundant and diverse microbial community (i.e., the oral microbiome), whose composition and roles in health and disease have been the focus of intense research in recent years. Thanks to developments in sequencing-based approaches, such as 16S ribosomal RNA metabarcoding, whole metagenome shotgun sequencing, or meta-transcriptomics, we now can efficiently explore the diversity and roles of oral microbes, even if unculturable. Recent sequencing-based studies have charted oral ecosystems and how they change due to lifestyle or disease conditions. As studies progress, there is increasing evidence of an important role of the oral microbiome in diverse health conditions, which are not limited to diseases of the oral cavity. This, in turn, opens new avenues for microbiome-based diagnostics and therapeutics that benefit from the easy accessibility of the oral cavity for microbiome monitoring and manipulation. Yet, many challenges remain ahead. In this review, we survey the main sequencing-based methodologies that are currently used to explore the oral microbiome and highlight major findings enabled by these approaches. Finally, we discuss future prospects in the field.

Oropharyngeal Microbiome in Obstructive Sleep Apnea: Decreased Diversity and Abundance

STUDY OBJECTIVES

To explore and analyze diversity and abundance of oropharyngeal microbiota in patients with obstructive sleep apnea (OSA).

METHODS

This was a cross-sectional study. Middle-aged men, suspected to have OSA, referred to full-night polysomnography, and willing to provide oropharyngeal swab samples, were consecutively enrolled. OSA severity was assessed by apnea-hypopnea index (AHI) as non-OSA (AHI < 5 events/h) and OSA (AHI ≥ 15 events/h). Bacterial DNA of oropharyngeal samples was extracted and quality test performed. Oropharyngeal microbiota was analyzed using 16S ribosomal DNA (rDNA) sequencing, and bioinformatic analysis carried out after sequencing.

RESULTS

Samples from 51 men (25 in the non-OSA group and 26 in the OSA group) were sent for examination. Of these, 40 samples were found to have sufficient concentration of DNA and were analyzed for bioinformatics. In alpha diversity analysis, the OSA group exhibited significantly lower sobs (198.33 ± 21.71 versus 216.57 ± 26.21, P = .022), chao (221.30 ± 26.62 versus 243.86 ± 26.20, P = .014), ace (222.17 ± 27.15 versus 242.42 ± 25.81, P = .028) and shannon index (3.14 ± 0.23 versus 3.31 ± 0.26, P = .035), suggesting a reduction in microbial species diversity. We further divided participants into non-OSA, moderate OSA, and severe OSA groups and observed a significant decrease in the bacterial biodiversity of OSA groups compared with the non-OSA group, with the most significant decrease occurring in the moderate OSA group. Principal coordinate analysis showed two extremely different oropharyngeal microbial communities in non-OSA and OSA groups. More interestingly, proportion of Neisseria was slightly higher in the severe OSA group (20.64%), followed by the moderate OSA and non-OSA groups (12.57% and 9.69%, respectively). Glaciecola was not detected in the OSA groups compared to the non-OSA group (0 versus 0.772 ± 0.4754, P < .001).

CONCLUSIONS

Middle-aged men with OSA showed less oropharyngeal species diversity and altered abundance, on which further confirmation is warranted.

Impact of maternal intrapartum antibiotics on the initial oral microbiome of neonates

OBJECTIVES

Prior studies have proposed that maternal intrapartum antibiotic exposure shapes the gut microbiota and, subsequently the child's health. However, the effect of maternal intrapartum antibiotic exposure and its influence on the development of the neonatal oral microbiota in early infancy has not yet been reported. The aim of this study was to compare the initial oral microbiota immediately after birth of healthy infants with and without intrapartum antibiotic exposure.

METHODS

Twenty-two newborns of the BaoAn Maternal and Child Care Hospital (Shenzhen, China) were recruited for this study, 11 born to mothers without intrapartum antibiotic exposure (NT group) and 11 to mothers with intrapartum antibiotic prophylaxis with cefamezin (AT group). Oral microbiome profiles were determined by 16S rRNA sequencing based on the V3V4 hyper-variable regions.

RESULTS

Phylum Firmicutes was most frequently detected in subjects both groups and a higher frequency was observed in the NT group than the AT group. Phyla Actinobacteria, Bacteroidetes and Proteobacteria were more abundant after intrapartum antibiotics exposure. Genus Lactobacillus belonging to Firmicutes was predominant in the neonates not exposed to antibiotics, while significantly higher percentages of genera Klebsiella, Roseburia, Propionibacterium, Faecalibacterium, Escherichia/Shigella, Corynebacterium, Bifidobacterium, and Bacteroides were noted in AT infants than NT infants. Further function analysis demonstrated that lipopolysaccharide biosynthesis and amino acid-related metabolic function was enriched in the AT group, and carbohydrate metabolism pathways were more abundant in the NT group.

CONCLUSIONS

These findings revealed distinctions in both taxa and metabolic function of oral microbiota between antibiotics-treated and unexposed groups, which indicated that maternal intrapartum antibiotic treatment is a key regulator of the initial neonatal oral microbiome.

Escherichia coli Clonobiome: Assessing the Strain Diversity in Feces and Urine by Deep Amplicon Sequencing

While microbiome studies have focused on diversity at the species level or higher, bacterial species in microbiomes are represented by different, often multiple, strains. These strains could be clonally and phenotypically very different, making assessment of strain content vital to a full understanding of microbiome function. This is especially important with respect to antibiotic-resistant strains, the clonal spread of which may be dependent on competition between them and susceptible strains from the same species. The pandemic, multidrug-resistant, and highly pathogenic Escherichia coli subclone ST131-H30 (H30) is of special interest, as it has already been found persisting in the gut and bladder in healthy people. In order to rapidly assess E. coli clonal diversity, we developed a novel method based on deep sequencing of two loci used for sequence typing, along with an algorithm for analysis of the resulting data. Using this method, we assessed fecal and urinary samples from healthy women carrying H30 and were able to uncover considerable diversity, including strains with frequencies at <1% of the E. coli population. We also found that, even in the absence of antibiotic use, H30 could completely dominate the gut and, especially, urine of healthy carriers. Our study offers a novel tool for assessing a species' clonal diversity (clonobiome) within the microbiome, which could be useful in studying the population structure and dynamics of multidrug-resistant and/or highly pathogenic strains in their natural environments.IMPORTANCE Bacterial species in the microbiome are often represented by multiple genetically and phenotypically different strains, making insight into subspecies diversity critical to a full understanding of the microbiome, especially with respect to opportunistic pathogens. However, methods allowing efficient high-throughput clonal typing are not currently available. This study combines a conventional E. coli typing method with deep amplicon sequencing to allow analysis of many samples concurrently. While our method was developed for E. coli, it may be adapted for other species, allowing microbiome researchers to assess clonal strain diversity in natural samples. Since assessment of subspecies diversity is particularly important for understanding the spread of antibiotic resistance, we applied our method to the study of a pandemic multidrug-resistant E. coli clone. The results we present suggest that this clone could be highly competitive in healthy carriers and that the mechanisms of colonization by such clones need to be studied.

The microbiome in autoimmune diseases

The microbiome is represented by microorganisms which live in a symbiotic way with the mammalian. Microorganisms have the ability to influence different physiological aspects such as the immune system, metabolism and behaviour. In recent years, several studies have highlighted the role of the microbiome in the pathogenesis of autoimmune diseases. Notably, in systemic lupus erythematosus an alteration of the intestinal flora (lower Firmicutes/Bacteroidetes ratio) has been described. Conversely, changes to the gut commensal and periodontal disease have been proposed as important factors in the pathogenesis of rheumatoid arthritis. At the same time, other autoimmune diseases (i.e. systemic sclerosis, Sjögren's syndrome and anti-phospholipid syndrome) also share modifications of the microbiome in the intestinal tract and oral flora. Herein, we describe the role of the microbiome in the maintenance homeostasis of the immune system and then the alterations of the microorganisms that occur in systemic autoimmune diseases. Finally, we will consider the use of probiotics and faecal transplantation as novel therapeutic targets.

Rheumatoid arthritis mediator CD18 expression by Staphylococcus aureus superantigen C in rats

BACKGROUND AND OBJECTIVES

Microbial superantigens have been reported in the blood and synovial fluid of rheumatoid arthritis patients, raising the question of whether the presence of these superantigens could provoke the induction of inflammatory biomarkers expression or not. The purpose of this study was to examine the Staphylococcus aureus superantigen C on CD18 expression.

MATERIALS AND METHODS

The superantigen C was purified by ultrafiltration. Immunoblotting was performed using a specific antibody. Also, 50 micrograms of superantigens (toxin) were injected intraperitoneally and intra-articularly into separate rat groups. Blood was collected and RNA extracted. Then, the cDNA was synthesized. The expression of CD18 marker was evaluated using RT-real-time PCR, and the results were descriptively analyzed.

RESULTS

The results of this study revealed that 50 μg of toxin, injected intra-articularly and intraperitoneally, showed the surplus expression of the marker CD18 in the blood of rats after 20 days. By this method, the expression of the marker CD18 was significantly different between rats that received the superantigen intra-articularly and intraperitoneally (2.10; 2.3 and 3.3 folds) and the controls (P≤ 0.05).

CONCLUSION

The results indicated that the presence of Staphylococcal of superantigen C in the body of rats has enhanced the expression of the CD18 inflammatory marker more than 3 times. This valuable finding is an introduction to further research and could provide new methods to prevent and control inflammatory diseases, including rheumatoid arthritis.

Rheumatoid arthritis patients' oral health and disease activity

AIM

Rheumatoid arthritis (RA) and periodontal diseases (PD) are common chronic, inflammatory, destructive and progressive diseases that may have similar pathophysiological mechanisms and risk factors. RA affects more than 1.5% of the world's population, with a higher percentage of females than males. PD is present in around 20% of the population and has multifactorial etiology. The purpose of this study is to describe patients' self-reported oral health and the association with RA disease activity.

METHOD

Three hundred patients under treatment for RA from the Division of Rheumatology, Clinical Medicine, North Jutland Region Hospital, Hjørring, Denmark and were eligible for the study. Questionnaires were emailed to the patients and 164 completed answers were received.

RESULTS

The mean age of the group of 164 patients (61% female) was 65 ± 11 years. The average value of Disease Activity Score of 28 joints was 2.31 ± 0.83. Only 12% of responders were active smokers. Patients estimated their status of their teeth and gingiva respectively as poor in 13% and 11% of cases, good, in 46% and 49%, and excellent, both as 40%. Spontaneous and/or provoked gingival bleeding were experienced by 15% and 49% of patients. Only 14% of patients declared feelings of loose or movable teeth and 10% declared difficulties in biting or chewing.

CONCLUSIONS

The status of oral cavity reported by Danish patients indicates a significant proportion with symptoms of gingival/periodontal disease, which may negatively influence RA activity and disease management. Cooperation between rheumatologists and dentists is important in oral health management in periodontal inflammation.

Cyclic Peptides in Neurological Disorders: The Case of Cyclo(His-Pro)

Communication between and within communities of cells or independent organisms is a crucial prerequisite for species survival. In response to variations in the extracellular environment, the collective behavior of cell populations can be coordinated by regulating community-level gene expression. This mechanism is strongly conserved during evolution, being shared both by bacterial communities and central nervous system cells. Notably, cyclic dipeptides (CDPs) are molecules that are implicated in these quorum sensing behaviors in both settings. Bacteria coordinate their collective behavior by producing CDPs (quorum sensing inducers) that enhance the capacity of individual members of the community to detect these signals and thus amplify the community-level response. In this review, we highlight recent data indicating that strikingly similar molecular mechanisms control communications between glial and neuronal cells to maintain homeostasis in the central nervous system, with a specific focus on the role of the thyrotropin-releasing hormone—derived CDP cyclo(His-Pro) in the protection against neurotoxic insults.

Oral microbiomes: more and more importance in oral cavity and whole body

Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and interaction of variable oral microorganisms help human body against invasion of undesirable stimulation outside. However, imbalance of microbial flora contributes to oral diseases and systemic diseases. Oral microbiomes play an important role in the human microbial community and human health. The use of recently developed molecular methods has greatly expanded our knowledge of the composition and function of the oral microbiome in health and disease. Studies in oral microbiomes and their interactions with microbiomes in variable body sites and variable health condition are critical in our cognition of our body and how to make effect on human health improvement.