Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease characterized by progressive demyelination, leading to the death of neurons in the central nervous system. Although the disease typically manifests itself in people aged 20–40 years, recent years have witnessed a rising incidence of early-onset MS. We assume that this may be due to the peculiarities of the gut microbiota taxonomic composition and its ability to produce B vitamins. This work was aimed to reveal changes in the gut microbiome composition in the onset of multiple sclerosis in children and adults, and to assess the potential of the gut microbiome to synthesise and metabolise B vitamins. The study included 15 children (aged 9–17 years) and 15 adults with MS manifested in childhood, as well as 14 adults over 35 years of age with MS duration less than one year. The gut microbiome composition was identified by sequencing the 16S rRNA gene on the Illumina platform with universal primers for the 16S rRNA V3–V4 variable region. The PICRUSt algorithm using the KEGG reference genome database was applied to predict the presence of B vitamin metabolic pathways in the gut microbiome. In the onset of MS, children exhibited specific microbiome changes different from those in adults, which included a decrease in alpha diversity, as well as a reduction in the dominant phyla and an increase in p_Verrucomicrobiota and p_Mycoplasmatota, accompanied by a decrease in the number of bacterial genes involved in metabolic and biosynthetic pathways of vitamins B1, B2, B3, B5 and B12. These changes may relate to the early manifestation of MS symptoms in children. Our findings accentuate the importance of further investigating the impact of the gut microbiome and its metabolic potential on MS development and progression, especially in childhood, and may contribute to the development of more effective methods to treat and prevent demyelinating diseases.

The preclinical stage of Parkinson’s disease (PD), when most dopaminergic neurons in the nigrostriatal system of the brain are still intact and compensatory mechanisms have not yet been overwhelmed, is the most effective “therapeutic window.” Much attention in recent years has therefore been focused on seeking early markers for the neurodegenerative process and developing experimental models. The present study addressed the task of analyzing early behavioral changes reflecting impairments in the cognitive and affective domains on modeling the premotor stage of PD in rats, with identification of the most informative tests. A model developed in our laboratory is based on a prolonged (21 days) preclinical stage of PD in rats by increasing suppression of the ubiquitin-proteasome system of the brain induced by two intranasal doses of the specific proteasome inhibitor lactacystin. Cognitive impairments were assessed using the novel object recognition and Y maze tests and the what–where–when paradigm. Anxiety was assessed in the elevated plus maze and open field tests. Administration of lactacystin was found to degrade spatial memory, episodic memory, and recognition of novel objects in rats on the background of a transient increase in the level of anxiety. These data suggest that impairments in the cognitive and affective domains may be early signs of the development of neurodegeneration in the brain.

At present, the role of intestinal microbiota in diverse diseases of the central nervous system, including of multiple sclerosis (MS) has been extensively investigated. Self-reactive CD4+ Th1 and Th17 cells specific to myelin-derived antigens play a key role in the MS pathogenesis. Taking into consideration pathogenetic features related to MS development, we examined a relation between intestinal microbiocenosis and abundance of various peripheral blood helper T (Th) cell subsets in MS patients. Objective of the study: to assess prevalence of individual members of the intestinal microbiota in MS patients and analyze a relation with peripheral blood Th cell subsets. Prevalence of symbiotic and opportunistic microbial species was estimated by bacteriological method and real time PCR in 112 MS patients (72 females, 40 males) of varying severity and duration. Th cell subsets (Th1, Th2, Th17, Th1/Th17, Th17/Th22, DP Th17) were analyzed by using multi-color flow cytometry based on Th cell subset-specific surface expression of chemokine receptors. A relationship between individual intestinal microbiota species and severity, duration and rate of MS progression, as well as with the phenotype of immune cells was assessed. It was found that the most significant correlation between percentage of peripheral blood Th cell subsets was observed with prevalence of Lactobacillus spp., Enterococcus spp. and Enterobacter spp. Moreover, prevalence of Enterococcus spp. Th cell composition influenced synergistically or antagonistically together with Enterobacter spp. or Lactobacillus spp., respectively. It is suggested that direct and indirect impact of intestinal microbiota composition on human immune system might contribute to developing novel strategies for treating MS.

Recent data demonstrate that disruption of the intestinal microbiocoenosis might be the cause of several neurological diseases, including multiple sclerosis (MS). MS is a chronic disease of the central nervous system, where the nervous tissue is damaged by the individual's own immune system. The autoimmune character of MS is largely supported by the positive effects of treatment aimed at suppressing the activity of aggressive immune cells. Since probiotics have an immunomodulatory effect, they can not only correct dysbiosis, but also provide a complex immunomodulatory effect on MS. Enterococcus faecium L-3 is one of the probiotic strains which has been shown to have a protective effect on the course of the disease induced in the animal model of MS (known as experimental allergic encephalomyelitis; EAE). The purpose of this study was to compare the effects of different doses of E. faecium L-3 on the course of EAE in rats. EAE was induced by a single subcutaneous injection of a homologous spinal cord emulsified into complete Freund's adjuvant. It is shown that the extent of the protective action of E. faecium L-3 depends on the dose used, with the greatest effect on reducing the severity of EAE observed with a dose of 8.0 lg CFU/ml. Amelioration of the course of EAE in rats receiving the probiotic was accompanied by decreased inflammation and reduced damage to neurons in the spinal cord. Research shows that the use of E. faecium L-3 at an optimum concentration of bacteria may be beneficial for patients with MS.

Recently, the role of the intestinal microbiota in MS has been actively investigated in connection with its influence the development and activity of immune and nervous systems. It is assumed that immune dysfunction, as well as disorders of the gastrointestinal tract and psycho-emotional functions in patients with MS, may be associated with intestinal microbiocenosis dysbiosis. The aim of the study was to assess changes in the intestinal microbiome in MS patients and to analyze the associations of the bacterial level with various subsets of Th cells in the blood and psycho-emotional disorders. 126 MS patients with disease duration of 12.2 ± 0.9 years and 69 healthy individuals were examined. Intestinal microbiome was determined by the Illumina/Solexa sequencing method. The quantitative content of microbial species was determined by the method of cultivation and real time PCR with specific primers, subsets of Th cells - by flow cytometry. Patients were assessed for anxiety, depression, and asthenia. It was shown that the intestinal microbiome of MS patients was significantly changed compared with healthy individuals: the proportion of Bacteroides, especially of the Prevotellaceae family, was reduced, the proportion of Firmicutes (Bacilli and Clostridia) and Actinobacteria was increased, and the symbiotic species in Enterobacteriaceae family were replaced by opportunistic species. A positive correlation between the level of Bifibobacteria spp. with disease severity and blood levels of DP Th17 CM cells. Enterobacter spp. level correlated with the level of “classical” or Th17/22 CM and DP Th17 EM. Bifidobacteria spp. the level was also associated with the level of depression in patients, the level of Escherichia coli and Prevotella spp. - with anxiety, and the level of atypical E. coli and Sutterella spp. - with asthenia. The data obtained suggest that immune and psycho-emotional disorders in patients with MS can be corrected by normalizing intestinal microbiocenosis.

At present, the role of intestinal microbiota in diverse diseases of the central nervous system, including of multiple sclerosis (MS) has been extensively investigated. Self-reactive CD4+ Th1 and Th17 cells specific to myelin-derived antigens play a key role in the MS pathogenesis. Taking into consideration pathogenetic features related to MS development, we examined a relation between intestinal microbiocenosis and abundance of various peripheral blood helper T (Th) cell subsets in MS patients. Objective of the study: to assess prevalence of individual members of the intestinal microbiota in MS patients and analyze a relation with peripheral blood Th cell subsets. Prevalence of symbiotic and opportunistic microbial species was estimated by bacteriological method and real time PCR in 112 MS patients (72 females, 40 males) of varying severity and duration. Th cell subsets (Th1, Th2, Th17, Th1/Th17, Th17/Th22, DP Th17) were analyzed by using multi-color flow cytometry based on Th cell subset-specific surface expression of chemokine receptors. A relationship between individual intestinal microbiota species and severity, duration and rate of MS progression, as well as with the phenotype of immune cells was assessed. It was found that the most significant correlation between percentage of peripheral blood Th cell subsets was observed with prevalence of Lactobacillus spp., Enterococcus spp. and Enterobacter spp. Moreover, prevalence of Enterococcus spp. Th cell composition influenced synergistically or antagonistically together with Enterobacter spp. or Lactobacillus spp., respectively. It is suggested that direct and indirect impact of intestinal microbiota composition on human immune system might contribute to developing novel strategies for treating MS.

AIM To describe characteristics of the intestinal microbiota in patients with multiple sclerosis (MS) treated with glatiramer acetate (GA) or fingolimode (FG) for understanding causal relationships between gut microbiota and autoimmune processes in MS patients. MATERIAL AND METHODS The study included 34 patients treated with GA (n=17) or FG (n=17). GA was used in a dose of 20 mg/kg subcutaneously once a day, FG in a dose of 0.5 mg daily. All patients were examined during remission. To assess the composition of gut microbiota, bacteriological and real-time PCR techniques were used. DNA was extracted from feces using DNA-EXPRESS kit. RESULTS AND CONCLUSION There was a decrease in numbers of Escherichia coli with normal enzymatic activity, which was replaced by atypical forms of E. coli, Enterobacter spp. and fungi of the genus Candida, and, during treatment with GA, by atypical forms of E. coli, Proteus spp., Parvimonas micra. These differences indicate the effect of the therapy on the intestinal microbiota composition.

Autoprobiotic (indigenous) strains of Enterococcus faecium used in the correction of experimental intestinal dysbiosis, in contrast to probiotic E. faecium strain L-3, had a marked bifidogenic effect, preserved the populations of Escherichia, and inhibited the growth of Proteus, but had a relatively low antagonistic activity in relation to Klebsiella. Administration of autoprobiotics (A) and probiotic (P) led to faster disappearance of the symptoms of dyspepsia as compared with the control group of rats (C1) in which dysbiosis was not corrected. Animals from subgroup A1 were given A, whose genomes contained a large number of pathogenicity genes, including cytolysins and hyaluronidase. Investigations using the open field test identified various behavioral reactions to correction of dysbiosis. Animals of subgroup A1 showed suppression of movement and orientational-investigative activity. In the second group of rats (subgroup A2), movement and orientational-investigative activity was comparable with that in control group C2 (without induction of dysbiosis), as after use of P. These characteristics of the effects of autoprobiotic enterococci on the intestinal microbiota and the body support the existence of an intestinal microbiome–brain axis.

The effect of N-decyltropine chloride (IEM-1556) and the reference drug glatiramer acetate (GA) on the severity of neurological disorders and the duration of the experimental allergic encephalomyelitis (EAE), modeling the processes of neural inflammation, demyelination and neurodegeneration characteristic for multiple sclerosis were studied. EAE in female Wistar rats was induced by a single subcutaneous (SC) inoculation of the homologous spinal cord homogenate in complete Freund’s adjuvant. The test preparations were administered from 2 to 16 days after induction of EAE. The severity of the disease was assessed in scores (from 0 to 6) by the presence in animals of persistent paresis and paralysis. The course systemic administration of IEM-1556 in a dose of 3 mg/kg reduced the severity and duration of EAE in rats, comparable to GA. Advantage of IEM-1556 before GA is the possibility of non-invasive application, as well as the presence of analgesic, antiparkinsonian and antidepressant action. It is assumed that the therapeutic effect of IEM-1556 is related to its ability to release endogenous adenosine, which causes neuroprotective, analgesic, antiparkinsonian and antidepressant effects of the drug.

An experimental model of the preclinical stage of Parkinson's disease was induced by double intranasal administration of the proteasome inhibitor lactacystin. The results demonstrated signs of cognitive impairments expressed as impaired non-associative learning. This was related to degeneration of one-third of dopaminergic neurons in the ventral tegmental area of the midbrain and their axons in the dorsolateral prefrontal cortex. Impairment of non-associative learning may be an early non-motor marker of Parkinson's disease indicating the start of neurodegenerative processes in the dopaminergic mesocortical system of the brain.

The research objective is comparison of psychoe motional state of patients suffering from disseminated sclerosis that were taking Enterococcus faecium L-3 and patients and that were not taking it. Research materials and methods. For evaluation of psychoe motional state of patients suffering from disse minated sclerosis two groups were created (control group and experimental group), each of the m amounted to 15 persons having definite diagnosis dissminated sclerosis. Standard questionnaires were used («Dominant condition» and «Actual condition» by L.V. Kulikov, questionnaire «Health,activ-ity,mood»,scale of situational (reactive) state anxiety by Ch.D. Spilberger and Yu.L. Khanin,and technique of differential diagnostics of depressive states by V. Zung). Results. After a course of probiotics intake indices at patients of experimental group (р<0.05) have been definitely improved in accordance withscales of the «Dominating state» questionnaire: «Relaxedness - potential stress» , «Evenness - psychic tension» , «Stability - instability of emotional background», «Satisfaction - dissatisfaction withlife in general» and in accordance withthe scale „Evenness - psychictension“ of the „Actual state“ questionnaire. Opinion. Obtained results bear evidence that the course intake of Enterococcus faecium L-3 has positive influence on psychoe motional state of patients having the diagnosis disse minated sclerosis.

We report here a study using a model of multiple sclerosis – experimental allergic encephalomyelitis (EAE) – to investigate changes in the qualitative and quantitative composition of the intestinal microbiota in rats with disease symptoms and with a symptom-free course. When clinical symptoms of EAE were apparent, there were changes in the composition of the microbiota of the gastrointestinal tract, with increases in the numbers of Gram-negative opportunistically pathogenic bacteria: Citrobacter spp., Klebsiella spp., and atypical E. coli . Rats without clinical signs of EAE were also found to have increased contents of Faecalibacterium prausnitzii . The significance of complexes changes in the composition of the intestinal microbiota is discussed, as this provides evidence of prolonged persistence of dysbacteriosis in rats on developing EAE.

The intestinal microbiota is currently regarded as a potential target for treatments in many pathologies underlying the genesis of inflammation, autoimmune reactions, and neurodegeneration. Multiple sclerosis (MS) is a disease whose pathogenesis combines all these processes. MS also involves impairment to the balance between the components of the intestinal microbiota, with development of dysbiosis. Various probiotics are widely used to correct dysbiotic conditions – bacteria with proven useful properties. We report here the use of a model of multiple sclerosis – experimental allergic encephalomyelitis (EAE) – to study the ability of the probiotic Enterococcus faecium strain L-3 to decrease disease severity in rats when used alone and in combination with glatiramer acetate (GA). Administration of E. faecium L-3 was found to decrease the severity of EAE in rats to essentially the same extent as GA. However, simultaneous use of probiotic enterococci with GA produced no protective action. It is suggested that these agents stimulate different components of the immune system, as their actions produce increases in different populations of immune cells circulating in the blood. The study results demonstrate the ability of E. faecium L-3 to produce significant direct and indirect (via correction of dysbacteriosis) influences on the immune system in MS, which allows these bacteria to be regarded as a potential agent for immunocorrection in autoimmune, inflammatory, and neurodegenerative disease.

The effect of probiotic Enterococcus faecium strain L-3 was studied in rats with experimental allergic encephalomyelitis (EAE). Glatiramer acetate (GA) was used as control drug. E. faecium strain L-3 and GA both were able to reduce the severity of EAE in a similar fashion. Both approaches increased the proportion of EAE resistant rats and rats with mild disease, prolonged the inductive phase of EAE and reduced the disease duration. Study of the phenotypes of immune cells in blood revealed the differences in immunoregulatory pathways that mediate the protective action of probiotic or GA treatment of EAE. The presence of pronounced protective and immunomodulating effects of the probiotic E. faecium strain L-3 opens an opportunity of its application for the treatment of multiple sclerosis.

Recent literature raises questions about the role of intestinal microbiota in the regulation of immune functions and in supporting of chronic inflammation upon numerous neurological conditions including multiple sclerosis (MS). On the other hand, almost 70% of MS patients have gastrointestinal problems. Study objective: Analysis of the qualitative and quantitative composition of intestinal microflora in MS patients. Materials and methods: The study group included 21 patients (14 females and 7 males). Intestinal microbiota was studied using bacteriological techniques and real-time polymerase chain reaction (RT PCR). Results: All patients were found to have alterations (dysbiosis) in the compositions of intestinal microbial populations manifested as decreases in symbiotic bacteria and the appearance and excessive proliferation of conditionally pathogenic microorganisms, there being certain intersex differences between patients: women showed decreased proportions of hormone-dependent lactobacilli and the excessive proliferation of weakly pathogenic atypical Escherichia, Citrobacter and Acinetobacter species, whereas men showed high rates of detection of S. aureus, Klebsiella sp., Proteus sp., and Candida fungi. The role of intestinal dysbiosis in the pathogenesis of MS and the possibility to treat disturbances in bacterial homeostasis with probiotics are discussed.

In this study, on the model of multiple sclerosis - experimental allergic encephalomyelitis (EAE), the dynamics of changes in the qualitative and quantitative composition of the intestinal microbiota in rats with symptoms of the disease and asymptomatic course were compared. It was found that the composition of the intestinal microbiota in rats with the clinical symptoms of EAE is shifted towards gram-negative opportunistic microorganisms of the genus Citrobacter, Prote- us, Klebsiella and enteropathogenic Escherichia coli. It has been shown that rats without clinical signs of EAE have higher levels of Faecalibacteriumprausnitzii. The significance of the complex changes in the composition of the intestinal microbiota, indicating long-lasting dysbiosis in rats during the development of EAE is discussing.