Prognostic value of stress hyperglycemia ratio on short- and long-term mortality after acute myocardial infarction

AIMS

Prior studies demonstrated an association between hospital admission blood glucose and mortality in acute myocardial infarction (AMI). Because stress hyperglycemia ratio (SHR) has been suggested as a more reliable marker of stress hyperglycemia this study investigated to what extent SHR in comparison with admission blood glucose is associated with short- and long-term mortality in diabetic and non-diabetic AMI patients.

METHODS

The analysis was based on 2,311 AMI patients aged 25-84 years from the population-based Myocardial Infarction Registry Augsburg (median follow-up time 6.5 years [IQR: 4.9-8.1]). The SHR was calculated as admission glucose (mg/dl)/(28.7 × HbA1c (%)-46.7). Using logistic and COX regression analyses the associations between SHR and admission glucose and mortality were investigated.

RESULT

Higher admission glucose and higher SHR were significantly and nonlinearly associated with higher 28-day mortality in AMI patients with and without diabetes. In patients without diabetes, the AUC for SHR was significantly lower than for admission glucose (SHR: 0.6912 [95%CI 0.6317-0.7496], admission glucose: 0.716 [95%CI 0.6572-0.7736], p-value: 0.0351). In patients with diabetes the AUCs were similar for SHR and admission glucose. Increasing admission glucose and SHR were significantly nonlinearly associated with higher 5-year all-cause mortality in AMI patients with diabetes but not in non-diabetic patients. AUC values indicated a comparable prediction of 5-year mortality for both measures in diabetic and non-diabetic patients.

CONCLUSIONS

Stress hyperglycemia in AMI patients plays a significant role mainly with regard to short-term prognosis, but barely so for long-term prognosis, underlining the assumption that it is a transient dynamic disorder that occurs to varying degrees during the acute event, thereby affecting prognosis.

978 ADVANCED CARE PLANNING IN PATIENTS WITH PARKINSONIAN DISORDERS

Introduction

Advanced care planning (ACP) supports individuals to make decisions regarding their future care. Guidelines (NICE, 2017) recommend offering ACP discussions to people with Parkinson’s Disease (PD), but uptake lags behind other countries (Sokol, NPJ Parkinson’s Dis, 2019, 22:5–24). As part of a project to improve ACP in the community we audited ACP practice at North Bristol NHS Trust.

Method

Records for 100 patients with idiopathic PD or atypical Parkinsonian syndromes seen in Movement Disorders clinics from March to October 2021 were scrutinised. ACP was defined as including: Do not attempt cardio-pulmonary resuscitation (DNACPR), Advanced Statement of Wishes, Advanced Decision to Refuse Treatment (ADRT) and Lasting Power of Attorney (LPOA). Disease severity was assessed using Hoehn and Yahr (H&Y) score.

Results

87 records were audited, 13 were excluded due to non-Parkinsonian disorders (11) or unavailable records (2). ACP was completed for 22 (25%) cases, (18 DNACPR and 11 Advanced Statements, 1 LPA, 0 ADRT). Informal ACP, such as documentation of wishes in clinic letters, were present in 5 cases. Of the 22 instances of ACP, 20 were recorded on Recommended Summary Plan for Emergency Care and Treatment (ReSPECT) forms. Preferences included ventilation (10), hospital admission (6), life prolonging treatments (6), preferred place of care (4), nutrition (0). Completed ACP was associated with higher H&Y scores or atypical syndromes.

Conclusion

It is recognised that there is a need to further investigate how ACP is delivered for patients with Parkinsonian Disorders. Three US studies estimated ACP rates ranging from 14.6%–53%. (Nimmons, European Journal of Neurology 2020, 27:1971–1987). We are not aware of any comparable UK data. This is a preliminary audit for a project to improve ACP within our MD Service. We are collecting further data on the views of our community movement disorders team with a view to upskilling in ACP.

Experimental helium-beam radiography with a high-energy beam: Water-equivalent thickness calibration and first image-quality results

PURPOSE

A clinical implementation of ion-beam radiography (iRad) is envisaged to provide a method for on-couch verification of ion-beam treatment plans. The aim of this work is to introduce and evaluate a method for quantitative water-equivalent thickness (WET) measurements for a specific helium-ion imaging system for WETs that are relevant for imaging thicker body parts in the future.

METHODS

Helium-beam radiographs (αRads) are measured at the Heidelberg Ion-beam Therapy Center (HIT) with an initial beam energy of 239.5 MeV/ u. An imaging system based on three pairs of thin silicon pixel detectors is used for ion path reconstruction and measuring the energy deposition (dE) of each particle behind the object to be imaged. The dE behind homogeneous plastic blocks is related to their well-known WETs between 280.6mm and 312.6 mm with a calibration curve that is created by fitting the measured data points. The quality of the quantitative WET measurements is determined by the uncertainty of the measured WET of a single ion (single-ion WET precision) and the deviation of a measured WET value to the well-known WET (WET accuracy). Subsequently, the fitted calibration curve is applied to an energy deposition radiograph of a phantom with a complex geometry. The spatial resolution (modulation transfer function at 10% (MTF_10% )) and WET accuracy (mean absolute percentage difference (MAPD)) of the WET map, are determined.

RESULTS

In the optimal imaging WET-range from ∼  280 mm to 300 mm, the fitted calibration curve reached a mean single-ion WET precision of 1.55 ± 0.00%. Applying the calibration to an ion radiograph (iRad) of a more complex WET distribution, the spatial resolution was determined to be MTF_10% = 0.49 ± 0.03 lp/mm and the WET accuracy was assessed as MAPD to 0.21%.

CONCLUSIONS

Using a beam energy of 239.5MeV/ u and the proposed calibration procedure, quantitative αRads of WETs between ∼  280mm to 300 mm can be measured and show high potential for clinical use. The proposed approach with the resulting image qualities encourages further investigation towards the clinical application of helium-beam radiography. This article is protected by copyright. All rights reserved.

A Spontaneous Model of Experimental Autoimmune Encephalomyelitis Provides Evidence of MOG-Specific B Cell Recruitment and Clonal Expansion

The key role of B cells in the pathophysiology of multiple sclerosis (MS) is supported by the presence of oligoclonal bands in the cerebrospinal fluid, by the association of meningeal ectopic B cell follicles with demyelination, axonal loss and reduction of astrocytes, as well as by the high efficacy of B lymphocyte depletion in controlling inflammatory parameters of MS. Here, we use a spontaneous model of experimental autoimmune encephalomyelitis (EAE) to study the clonality of the B cell response targeting myelin oligodendrocyte glycoprotein (MOG). In particular, 94% of SJL/j mice expressing an I-A^s: MOG_92-106 specific transgenic T cell receptor (TCR¹⁶⁴⁰) spontaneously develop a chronic paralytic EAE between the age of 60-500 days. The immune response is triggered by the microbiota in the gut-associated lymphoid tissue, while there is evidence that the maturation of the autoimmune demyelinating response might occur in the cervical lymph nodes owing to local brain drainage. Using MOG-protein-tetramers we tracked the autoantigen-specific B cells and localized their enrichment to the cervical lymph nodes and among the brain immune infiltrate. MOG-specific IgG1 antibodies were detected in the serum of diseased TCR¹⁶⁴⁰ mice and proved pathogenic upon adoptive transfer into disease-prone recipients. The ontogeny of the MOG-specific humoral response preceded disease onset coherent with their contribution to EAE initiation. This humoral response was, however, not sufficient for disease induction as MOG-antibodies could be detected at the age of 69 days in a model with an average age of onset of 197 days. To assess the MOG-specific B cell repertoire we FACS-sorted MOG-tetramer binding cells and clonally expand them in vitro to sequence the paratopes of the IgG heavy chain and kappa light chains. Despite the fragility of clonally expanding MOG-tetramer binding effector B cells, our results indicate the selection of a common CDR-3 clonotype among the Igk light chains derived from both disease-free and diseased TCR¹⁶⁴⁰ mice. Our study demonstrates the pre-clinical mobilization of the MOG-specific B cell response within the brain-draining cervical lymph nodes, and reiterates that MOG antibodies are a poor biomarker of disease onset and progression.

Endoscopic grading systems for nasal polyps: are we comparing apples to oranges?

Endoscopic grading of nasal polyps (NP) is typically a coprimary endpoint in clinical trials evaluating treatments for chronic rhinosinusitis with nasal polyps (CRSwNP). However, a consensus on the most effective way to grade nasal polyps has not been reached. Different scales have been used, hampering the interpretation of data across trials. This review compares the characteristics of NP grading systems used in registration trials for approved NP treatments. These fundamental differences in grading systems make quantitative comparison of outcomes between trials inaccurate and potentially misleading. In lieu of a universal grading system, reporting the baseline distribution of polyp grades (unilateral and/or summed/total grades), as well as changes from baseline over time by baseline grade may help improve interpretability of outcomes and reduce inaccuracy when attempting cross-trial comparisons and making therapeutic decisions.

T cells modulate the microglial response to brain ischemia

Neuroinflammation after stroke is characterized by the activation of resident microglia and the invasion of circulating leukocytes into the brain. Although lymphocytes infiltrate the brain in small number, they have been consistently demonstrated to be the most potent leukocyte subpopulation contributing to secondary inflammatory brain injury. However, the exact mechanism of how this minimal number of lymphocytes can profoundly affect stroke outcome is still largely elusive. Here, using a mouse model for ischemic stroke, we demonstrated that early activation of microglia in response to stroke is differentially regulated by distinct T cell subpopulations - with T_H1 cells inducing a type I INF signaling in microglia and regulatory T cells (T_REG) cells promoting microglial genes associated with chemotaxis. Acute treatment with engineered T cells overexpressing IL-10 administered into the cisterna magna after stroke induces a switch of microglial gene expression to a profile associated with pro-regenerative functions. Whereas microglia polarization by T cell subsets did not affect the acute development of the infarct volume, these findings substantiate the role of T cells in stroke by polarizing the microglial phenotype. Targeting T cell-microglia interactions can have direct translational relevance for further development of immune-targeted therapies for stroke and other neuroinflammatory conditions.

Gender-linked determinants for utilization of long-term care in community-dwelling adults in Germany

Background

The number of people using long-term care (LTC) is increasing steadily worldwide. Hence, demand for adequate services is rising. The purpose of this exploratory study was to identify relevant gender-linked determinants for utilization of LTC in community-dwelling older adults.

Methods

We examined 4077 females (52.7%) and males ≥ 65 years old (range: 65-97) between 2011/12 (t1) and 2016 (t2). Data originated from the population-based Cooperative Health Research in the Region of Augsburg (KORA)-Age study in Germany. A descriptive analysis assessed the amount of LTC used. Cross-sectional generalized estimating equation logistic models identified determinants for utilization of (in)formal LTC. Determinants for transition to LTC between t1 and t2 were examined using a longitudinal logistic regression model. Potential determinants were chosen according to Andersen's Behavioral Model of Health Services Use.

Results

At t2, 820 (20.1%) were LTC users with 527 (64.3%) being female. The average amount of informal LTC was higher in males (158.0 minutes/day (m/d) (SD: 270.5) vs. 70.1 m/d (SD: 152.8)), whereas the amount of formal LTC was higher in females (89.7 m/d (SD: 224.7) vs. 28.5 m/d (SD: 23.3)). In both genders, higher age, multimorbidity, and disability were associated with utilization of and transition to LTC. Living alone was significantly associated with utilization of (formal) LTC in both genders, but its effect was almost two times stronger in males (men: OR: 3.48 (CI: 2.05-5.90) vs females: OR: 1.83 (CI: 1.25-2.69)). Thus, ‘living alone' is considered the essential gender-linked determinant.

Conclusions

Gender-linked determinants must be considered when establishing demand-oriented policies. Future health programs should specifically target older individuals, especially males, living alone to improve their capabilities in activities of daily living to allow them to remain living longer and more independently within community settings.

Key messages

Older individuals, especially men, living alone should be targeted in future health programs. Females tend to use a higher amount of formal long-term care than males.

Association of glycated haemoglobin A1c levels with cardiovascular outcomes in the general population: results from the BiomarCaRE consortium

Background

Glycated haemoglobin A1c (HbA1c) is used to monitor the quality of diabetes treatment; however, its role in predicting cardiovascular outcomes in the general population remains uncertain.

Purpose

The additional use of glycated haemoglobin A1c (HbA1c) as a biomarker might highlight subjects of the general population with an increased risk for cardiovascular outcomes with cardiovascular disease, cardiovascular mortality or overall-mortality.

Methods

Data from six prospective population-based cohort studies across Europe comprising 36,180 participants were analysed. HbA1c was evaluated in conjunction with classical cardiovascular risk factors (CVRFs) for association with cardiovascular mortality, cardiovascular diseases (CVD), and overall mortality in the study population, in non-diabetic (N=32,477), and diabetic participants (N=3,703).

Results

Kaplan-Meier curves showed higher event rates with increasing continuous log-transformed HbA1c levels. Cox regression analysis revealed significant associations between HbA1c (in mmol/mol) log-transformed divided by interquartile range and the examined outcomes, with a hazard ratio (HR) of 1.12 (95% confidence interval (CI): 1.04–1.20, p=0.0019) for cardiovascular mortality, 1.10 (95% CI: 1.04–1.16, p<0.001) for CVD, and 1.09 (95% CI: 1.05–1.14, p<0.001) for overall mortality per one unit increase.

An increased risk of CVD was observed in subjects without diabetes with increased HbA1c levels (HR 1.09; 95% CI: 1.01–1.16, p=0.021). An HbA1c cut-off value of 39.89 mmol/mol (5.8%), 36.62 mmol/mol (5.5%), and 38.80 mmol/mol (5.7%) for cardiovascular mortality, CVD, and overall mortality, respectively, was determined for selecting individuals at an increased risk.

Conclusion

HbA1c was demonstrated to be an independent prognostic biomarker for all investigated outcomes in the general European population. An approximately linear relationship was observed between an increase of HbA1c levels and the outcomes. Elevated HbA1c levels were also associated with the outcomes in participants without diabetes (i.e. HbA1c levels <6.5% (<48mmol/mol) which underlines the importance of HbA1c levels in the overall population.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Seventh Framework ProgrammeEuropean Union FP 7 project CHANCES Kaplan-Meier curves for the outcomesPenalised cubic splines HbA1c/time event

Host traits, lifestyle and environment are associated with human skin bacteria

BACKGROUND

The human skin offers diverse ecosystems for microbial symbionts. However, the factors shaping skin-microbiome interactions are still insufficiently characterized. This contrasts with the broader knowledge about factors influencing gut microbiota.

OBJECTIVES

We aimed to investigate major patterns of association of host traits, lifestyle and environmental factors with skin bacteria in two German populations.

METHODS

This is a cross-sectional study with 647 participants from two population-based German cohorts, PopGen (n = 294) and KORA FF4 (n = 353), totalling 1794 skin samples. The V1-V2 regions of the 16S ribosomal RNA (rRNA) gene were sequenced. Associations were tested with two bacterial levels, community (beta diversity) and 16S rRNA gene amplicon sequence variants (ASVs).

RESULTS

We validated known associations of the skin microbiota with skin microenvironment, age, body mass index and sex. These factors were associated with beta diversity and abundance of ASVs in PopGen, which was largely replicated in KORA FF4. Most intriguingly, dietary macronutrients and total dietary energy were associated with several ASVs. ASVs were also associated with smoking, alcohol consumption, skin pH, skin type, transepidermal water loss, education and several environmental exposures, including hours spent outdoors. Associated ASVs included members of the genera Propionibacterium, Corynebacterium and Staphylococcus.

CONCLUSIONS

We expand the current understanding of factors associated with the skin bacterial community. We show the association of diet with skin bacteria. Finally, we hypothesize that the skin microenvironment and host physiology would shape the skin bacterial community to a greater extent compared with a single skin physiological feature, lifestyle and environmental exposure.

Presumptive neural microsporidiosis in a young adult German Shepherd dog from rural Australia

CASE REPORT

A 1-year-old, neutered male German Shepherd was presented with a 5-month history of episodic lethargy, intermittent fever, weight loss and a hunched posture. The dog was diagnosed with presumptive microsporidian meningoencephalitis based on cytological findings on cerebrospinal fluid analysis and a positive PCR test. The dog initially responded favourably to a 4-week course of trimethoprim-sulfadiazine, pyrimethamine and fenbendazole, and remained well for 12 weeks following cessation of treatment. Disease then recurred, and despite an initial positive response to treatment, he deteriorated and was euthanased 11 weeks later, 7.5 months after definitive diagnosis and 13 months after clinical signs were first reported.

CONCLUSION

To the authors knowledge, this is the first case of canine microsporidiosis in Australia.

Developing understanding of the fate and behaviour of silver in fresh waters and waste waters

The Windermere Humic Aqueous Model (WHAM) is often used for risk assessment of metals; WHAM can be used to estimate the potential bioavailability of dissolved metals, where metals complexed to dissolved organic matter (DOM) are expected to be less toxic than ionic forms. Silver is a potential metal of concern but WHAM has not been rigorously tested against experimental measurements. This study compares WHAM predictions to measured ionic silver during fixed pH (4, 8 or 10) argentometric titrations of DOM from diverse origins. There were almost two orders of magnitude variation in free silver between sources but, within model uncertainty, WHAM captured this variability. This agreement, between measurements and models, suggests that WHAM is an appropriate tool for silver risk assessment in surface receiving waters when DOM is predominantly in the form of humic/fulvic acids. In sewage samples WHAM dramatically underestimated silver binding by approximately 3 orders of magnitude. Simulations with additional specific strong silver binding sulphide-like binding sites could explain Ag binding at low loadings, but not at higher loadings. This suggests the presence of additional intermediate strength binding sites. These additional ligands would represent components of the raw sewage largely absent in natural waters unimpacted by sewage effluents. A revised empirical model was proposed to account for these sewage-specific binding sites. Further, it is suspected that as sewage organic matter is degraded, either by natural attenuation or by engineered treatment, that sewage organic matter will degrade to a form more readily modelled by WHAM; i.e., humic-like substances. These ageing experiments were performed starting from raw sewage, and the material did in fact become more humic-like, but even after 30 days of aerobic incubation still showed greater Ag⁺ binding than WHAM predictions. In these incubation experiments it was found that silver (up to 1000 μg/L) had minimal impact on ammonia oxidation kinetics.

Salt generates antiinflammatory Th17 cells but amplifies pathogenicity in proinflammatory cytokine microenvironments

Th cells integrate signals from their microenvironment to acquire distinct specialization programs for efficient clearance of diverse pathogens or for immunotolerance. Ionic signals have recently been demonstrated to affect T cell polarization and function. Sodium chloride (NaCl) was proposed to accumulate in peripheral tissues upon dietary intake and to promote autoimmunity via the Th17 cell axis. Here, we demonstrate that high-NaCl conditions induced a stable, pathogen-specific, antiinflammatory Th17 cell fate in human T cells in vitro. The p38/MAPK pathway, involving NFAT5 and SGK1, regulated FoxP3 and IL-17A expression in high-NaCl conditions. The NaCl-induced acquisition of an antiinflammatory Th17 cell fate was confirmed in vivo in an experimental autoimmune encephalomyelitis (EAE) mouse model, which demonstrated strongly reduced disease symptoms upon transfer of T cells polarized in high-NaCl conditions. However, NaCl was coopted to promote murine and human Th17 cell pathogenicity, if T cell stimulation occurred in a proinflammatory and TGF-β-low cytokine microenvironment. Taken together, our findings reveal a context-dependent, dichotomous role for NaCl in shaping Th17 cell pathogenicity. NaCl might therefore prove beneficial for the treatment of chronic inflammatory diseases in combination with cytokine-blocking drugs.

Cardiac troponin I and incident stroke in European cohorts – insights from the BiomarCaRE project

Background

Stroke is a common cause of death and a leading cause of disability and morbidity. Stroke risk assessment remains a challenge but circulating biomarkers may improve risk prediction. Controversial evidence is available on the predictive ability of troponin concentrations and the risk of stroke in the community. Furthermore, reports on the predictive value of troponin concentrations for different stroke subtypes (ischemic and hemorrhagic) are scarce.

Methods

High-sensitivity cardiac troponin I (hsTnI) concentrations were assessed in 82,881 individuals (median age 50.7 years, 49.7% men) free of stroke or myocardial infarction at baseline from nine prospective European community cohorts. Multiple imputations were used to handle missing data. We used Cox proportional hazards regression to determine relative risks, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for over-optimism. Follow-up was based upon linkage with national hospitalization registries and causes of death registries.

Results

Over a median follow-up of 12.7 years, 3,033 individuals were diagnosed with incident non-fatal or fatal stroke (N=1,654 ischemic strokes, N=612 hemorrhagic strokes, N=767 indeterminate strokes). In multivariable regression models hsTnI concentrations were associated with overall stroke (hazard ratio (HR) per one standard deviation increase 1.16, 95% confidence interval (CI) 1.10–1.21), ischemic stroke (HR 1.15, 95% CI 1.09–1.21) and hemorrhagic stroke (HR 1.10, 95% CI 1.01–1.21). Adding hsTnI concentrations to classical cardiovascular risk factors (C-indices 0.808, 0.840 and 0.735 for overall, ischemic and hemorrhagic stroke, respectively) increased the C-index significantly, but modestly. In individuals with an intermediate ten-year risk (5–20%) the net reclassification improvement for overall stroke was 0.039 (p=0.010).

Conclusions

Elevated hsTnI concentrations are associated with an increased risk of incident stroke in the community, irrespective of stroke subtype. Adding hsTnI concentrations to classical risk factors only modestly improved estimation of 10-year risk of stroke in the overall cohort, but might be of some value in individuals at an intermediate risk.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): The BiomarCaRE Project is funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no.HEALTH-F2-2011-278913. This project has received further funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 648131).

Telomere length is associated with atrial fibrillation

Background

Atrial Fibrillation (AF) is common and is caused and predisposed to by a complex pathophysiology. Aging is among the most important risk factors for AF. Yet, some individuals develop AF in early years, whereas elderly individuals may remain free of AF. Aside from measurable concomitant risks, we hypothesized that a pathophysiologically relevant biological age exists, which outweighs a patient's calendar age. Telomere length is a measurable marker of age, which might reflect biological age. AF and telomere length have previously been associated, but results remained controversial. Here, we tested the relation between AF and telomere length in a well-characterized and so far largest cohort.

Methods

Since 2005, we enrolled 2475 patients with AF from the prospective AFLMU cohort, preferentially if they developed AF before age 65 years, and 3077 control individuals free of AF from the community-based KORA Study between 2006–08. All participants received a detailed clinical characterization, an electrocardiogram, and a blood draw for biomarker analyses. In all participants, we determined telomere length using a qPCR-based method. In a 384 well format, we employed a multiplex TaqMan assay to determine both telomere length and the single copy gene 36B4. Telomere length was expressed by the delta-CT method and was reformatted to have lower CT values indicate shorter telomere length. We compared telomere length between cases and controls using multi-variably corrected logistic regression models.

Results

Our cohort's mean age was 58 years in AFLMU and 56 years in KORA F4. Men were enrolled more commonly, with 72.3% in AFLMU and 51.7% in KORA F4. For consistency with available information, we confirmed that telomere length is continuously decreasing with age and that men have shorter telomere length compared to women. As a main result we found that AF patients have significantly shorter telomere length compared to controls (controls: telomere length 13,10 [12.60, 13.63] versus AF: 9.81 [5.98, 13.1], p<0,001). This relation remained significant following multi-variable adjustment for sex, body mass index, hypertension, and diabetes. The odds ratio per unit longer telomer length was 0.77 [95% confidence interval 0.74–0.77], p<0.001. We also calculated a propensity-score matched model of cases with and without AF confirming our main results (controls: telomere length 13.21 [11.65, 13.67] versus AF: 9.03 [5.35, 12.54], p<0.001). The multi-variable adjusted model revealed an odds ratio of 0,75 [95% confidence interval 0.73–0.76], p<0.001.

Conclusion

AF is significantly associated with telomere length in one of the largest cohorts to date. Assessment of telomere length may adjudicate patients with AF due to premature biological aging. The underlying reasons for such premature aging remain to be identified.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): European Commission - Horizon 2020

[Microbiota and multiple sclerosis]

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system driven by autoreactive lymphocytes. Due to its close contact with the gut-associated lymphoid tissue, the intestinal microbiota and/or their metabolites may be one of the factors that influence the activation of autoreactive lymphocytes. This article summarizes and discusses the current research efforts to characterize the microbiome of MS patients using human material. In addition, we present research studies that utilized classical or humanized animal models to determine the influence of certain microbiota species or compositions of microbiota on the immune system and disease progression and to define possible causal associations.