Oral administration of probiotic bacteria, Lactobacillus casei and Bifidobacterium breve, does not exacerbate neurological symptoms in experimental autoimmune encephalomyelitis

Bifidobacterium breve Probiotic Compared to Lactobacillus casei Causes a Better Reduction in Demyelination and Oxidative Stress in Cuprizone-Induced Demyelination Model of Rat

Despite the anatomical separation, strong evidence suggested a bidirectional association between gut microbiota and central nervous system. Cross-talk between gut microbiota and brain has an important role in the pathophysiology of neurodegenerative disorders and regenerative processes. However, choosing the appropriate probiotics and combination therapy of probiotics to provide a synergistic effect is very crucial. In the present study, we investigated the effect of Lactobacillus casei (L. casei) and Bifidobacterium breve (B. breve) on alternation performance, oxidant/antioxidant biomarkers, the extent of demyelination, and the expression level of HO-1, Nrf-2, Olig2, MBP, PDGFRα, and BDNF in cuprizone (CPZ)-induced demyelination model of rat corpus callosum. In order to induce this model, rats received oral administration of CPZ 0.6% w/w in corn oil for 28 days. Then, L. casei, B. breve, or their combinations were orally administrated for 28 days. Y maze test was performed to investigate the alternation performance. Oxidant/antioxidant biomarkers were determined by colorimetric methods. Extent of demyelination was investigated using FluoroMyelin staining. The genes' expression levels of antioxidant and myelin lineage cells were assessed by quantitative real time PCR. The results showed the probiotics supplementation significantly improve the alternation performance and antioxidant capacity in demyelinated corpus callosum. Interestingly, B. breve supplementation alleviated demyelination and oxidative stress levels more than the administration of L. casei alone or the combination of two probiotics. These observations suggest that B. breve could provide a supplementary strategy for the treatment of multiple sclerosis by increasing antioxidant capacity and remyelination.

The effect of probiotics on immune responses and their therapeutic application: A new treatment option for multiple sclerosis

Multiple sclerosis (MS) is known as a chronic inflammatory disease (CID) that affects the central nervous system and leads to nerve demyelination. However, the exact cause of MS is unknown, but immune system regulation and inhibiting the function of inflammatory pathways may have a beneficial effect on controlling and improving the disease. Studies show that probiotics can alter the gut microbiome, thereby improving and affecting the immune system and inflammatory responses in patients with MS. The results show that probiotics have a good effect on the recovery of patients with MS in humans and animals. The present study investigated the effect of probiotics and possible therapeutic mechanisms of probiotics on immune cells and inflammatory cytokines. This review article showed that probiotics could improve immune cells and inflammatory cytokines in patients with MS and can play an effective role in disease management and control.

The efficacy of probiotics in experimental autoimmune encephalomyelitis (an animal model for MS): a systematic review and meta-analysis

Probiotics immunomodulatory properties and their beneficial effects for diseases such as multiple sclerosis (MS) are reported by several studies. The current systematic review and meta-analysis aimed to investigate the favourable effects of probiotics in improving experimental autoimmune/allergic encephalomyelitis (EAE) as an animal model of MS. We systematically searched Scopus, Web of Sciences (ISI), and PubMed databases to identify relevant studies from the inception of these databases to December 2019. A total of 15 animal studies met the inclusion criteria, while no human study met the inclusion criteria. The association between consumption of probiotics and each sign was calculated using the producing pooled odd ratios (95% confidence interval [95% CI]) in a random effect model. The meta-analysis revealed the significant effect of probiotics on the incidence of EAE, weight gain, and clinical symptoms. However, the effects of probiotics on the duration of the disease varied by probiotic strain. The administration of probiotics was associated with a significant reduction in the risk of mortality only in female animals. Moreover, the meta-analysis revealed the promising effects of probiotics on the prevention and management of EAE.

Efficacy of probiotics in multiple sclerosis: a systematic review of preclinical trials and meta-analysis of randomized controlled trials

Preliminary evidence shows the potential role of probiotics in ameliorating multiple sclerosis (MS); however, the effects of probiotics on MS remain unclear.

Probiotic and commensal gut microbial therapies in multiple sclerosis and its animal models: a comprehensive review

The need for alternative treatments for multiple sclerosis (MS) has triggered copious amounts of research into microbial therapies focused on manipulating the microbiota-gut-brain axis. This comprehensive review was intended to present and systematically evaluate the current clinical and preclinical evidence for various probiotic and commensal gut microbial therapies as treatments for MS, using the Bradford Hill criteria (BHC) as a multi-parameter assessment rubric. Literature searches were performed to identify a total of 37 relevant studies (6 human, 31 animal), including 28 probiotic therapy and 9 commensal therapy studies. In addition to presenting qualitative summaries of these findings, therapeutic evidence for each bacterial formulation was assessed using the BHC to generate summative scores. These scores, which encompassed study quality, replication, and other considerations, were used to rank the most promising therapies and highlight deficiencies. Several therapeutic formulations, including VSL#3, Lactobacillus paracasei, Bifidobacterium animalis, E. coli Nissle 1917, and Prevotella histicola, emerged as the most promising. In contrast, a number of other therapies were hindered by limited evidence of replicable findings and other criteria, which need to be addressed by future studies in order to harness gut microbial therapies to ultimately provide cheaper, safer, and more durable treatments for MS.

Immunomodulatory and anti-inflammatory effects of probiotics in multiple sclerosis: a systematic review

Multiple sclerosis (MS) is an inflammatory and autoimmune neurological disorder which leads to demyelination. Although the etiology of MS is yet to be known, it appears that regulating the immune system and suppressing inflammatory pathways may possibly have a favorable effect on the healing of this disease. Evidence suggests that probiotics consumption via gut microbiome alteration devises beneficial effects in improving immune and inflammatory responses in MS. All articles were systematically searched (in the main databases) for this paper. Two investigators independently scrutinized full texts of the potentially eligible articles. The quality of the study was evaluated using standardized tools. The methodological quality of seven studies included in this review ranged from fair to good. The findings illustrated that there were statistically significant improvements in the static and dynamic balance in patients and animals with MS. In the paper in hand, the effects of probiotics administration on immune and inflammatory markers in MS disease are evaluated. In addition, the limitations and knowledge gaps were reported while proposing a possible mechanism of probiotics therapy in modulating immune and inflammatory responses. This systematic review indicated that the probiotics could improve immune and inflammatory parameters, the cytokines and cells in MS disease. Probiotics may have efficient effects in management and treatment of MS. More studies are required to clarify the effect of supplementation with probiotics and their mechanisms in MS disease.

Lactobacillus reuteri Reduces the Severity of Experimental Autoimmune Encephalomyelitis in Mice by Modulating Gut Microbiota

The gut microbiome plays an important role in immune function and has been implicated in multiple sclerosis (MS). However, how and if the modulation of microbiota can prevent or treat MS remain largely unknown. In this study, we showed that probiotic Lactobacillus reuteri DSM 17938 (L. reuteri) ameliorated the development of murine experimental autoimmune encephalomyelitis (EAE), a widely used animal model of MS, a model which is primarily mediated by T_H17 and T_H1 cells. We discovered that L. reuteri treatment reduced T_H1/T_H17 cells and their associated cytokines IFN-γ/IL-17 in EAE mice. We also showed that the loss of diversity of gut microbiota induced by EAE was largely restored by L. reuteri treatment. Taxonomy-based analysis of gut microbiota showed that three “beneficial” genera Bifidobacterium, Prevotella, and Lactobacillus were negatively correlated with EAE clinical severity, whereas the genera Anaeroplasma, Rikenellaceae, and Clostridium were positively correlated with disease severity. Notably, L. reuteri treatment coordinately altered the relative abundance of these EAE-associated taxa. In conclusion, probiotic L. reuteri changed gut microbiota to modulate immune responses in EAE, making it a novel candidate in future studies to modify the severity of MS.

Administration of bifidobacterium and lactobacillus strains modulates experimental myasthenia gravis and experimental encephalomyelitis in Lewis rats

Probiotics beneficial effects on the host are associated with regulation of the intestinal microbial homeostasis and with modulation of inflammatory immune responses in the gut and in periphery. In this study, we investigated the clinical efficacy of two lactobacillus and two bifidobacterium probiotic strains in experimental autoimmune myasthenia gravis (EAMG) and experimental autoimmune encephalomyelitis (EAE) models, induced in Lewis rats. Treatment with probiotics led to less severe disease manifestation in both models; ex vivo analyses showed preservation of neuromuscular junction in EAMG and myelin content in EAE spinal cord. Immunoregulatory transcripts were found differentially expressed in gut associated lymphoid tissue and in peripheral immunocompetent organs. Feeding EAMG animals with probiotics resulted in increased levels of Transforming Growth Factor-β (TGFβ) in serum, and increased percentages of regulatory T cells (Treg) in peripheral blood leukocyte. Exposure of immature dendritic cells to probiotics induced their maturation toward an immunomodulatory phenotype, and secretion of TGFβ. Our data showed that bifidobacteria and lactobacilli treatment effectively modulates disease symptoms in EAMG and EAE models, and support further investigations to evaluate their use in autoimmune diseases.

Variations in diet cause alterations in microbiota and metabolites that follow changes in disease severity in a multiple sclerosis model

Multiple sclerosis (MS) is a metabolically demanding disease involving immune-mediated destruction of myelin in the central nervous system. We previously demonstrated a significant alteration in disease course in the experimental autoimmune encephalomyelitis (EAE) preclinical model of MS due to diet. Based on the established crosstalk between metabolism and gut microbiota, we took an unbiased sampling of microbiota, in the stool, and metabolites, in the serum and stool, from mice (Mus musculus) on the two different diets, the Teklad global soy protein-free extruded rodent diet (irradiated diet) and the Teklad sterilisable rodent diet (autoclaved diet). Within the microbiota, the genus Lactobacillus was found to be inversely correlated with EAE severity. Therapeutic treatment with Lactobacillus paracasei resulted in a significant reduction in the incidence of disease, clinical scores and the amount of weight loss in EAE mice. Within the metabolites, we identified shifts in glycolysis and the tricarboxylic acid cycle that may explain the differences in disease severity between the different diets in EAE. This work begins to elucidate the relationship between diet, microbiota and metabolism in the EAE preclinical model of MS and identifies targets for further study with the goal to more specifically probe the complex metabolic interaction at play in EAE that may have translational relevance to MS patients.

Immunological and Clinical Effect of Diet Modulation of the Gut Microbiome in Multiple Sclerosis Patients: A Pilot Study

Pathogenesis of autoimmune disorders, including multiple sclerosis (MS), has been linked to an alteration of the resident microbial commensal community and of the interplay between the microbiota and the immune system. Dietary components such as fiber, acting on microbiota composition, could, in principle, result in immune modulation and, thus, could be used to obtain beneficial outcomes for patients. We verified this hypothesis in a pilot study involving two groups of clinically similar relapsing-remitting (RR) MS patients who had undergone either a high-vegetable/low-protein diet (HV/LP diet group; N = 10) or a "Western Diet" (WD group; N = 10) for at least 12 months. Gut microbiota composition, analyzed by 16 S V4 rRNA gene sequencing and immunological profiles, was examined after a minimum of 12 months of diet. Results showed that, in the HV/LP diet group compared to the WD group: (1) Lachnospiraceae family was significantly more abundant; (2) IL-17-producing T CD4+ lymphocytes (p = 0.04) and PD-1 expressing T CD4+ lymphocytes (p = 0.0004) were significantly decreased; and (3) PD-L1 expressing monocytes (p = 0.009) were significantly increased. In the HV/LP diet group, positive correlations between Lachnospiraceae and both CD14+/IL-10+ and CD14+/TGFβ+monocytes (R_Sp = 0.707, p = 0.05, and R_Sp = 0.73, p = 0.04, respectively), as well as between Lachnospiraceae and CD4+/CD25+/FoxP3+ T lymphocytes (R_Sp = 0.68, p = 0.02) were observed. Evaluation of clinical parameters showed that in the HV/LP diet group alone the relapse rate during the 12 months follow-up period and the Expanded Disability Status Scale score at the end of the study period were significantly reduced. Diet modulates dysbiosis and improves clinical parameters in MS patients by increasing anti-inflammatory circuits. Because Lachnospiraceae favor Treg differentiation as well as TGFβ and IL-10 production this effect could be associated with an increase of these bacteria in the microbiota.

Microbiome, probiotics and neurodegenerative diseases: deciphering the gut brain axis

The gut microbiota is essential to health and has recently become a target for live bacterial cell biotherapies for various chronic diseases including metabolic syndrome, diabetes, obesity and neurodegenerative disease. Probiotic biotherapies are known to create a healthy gut environment by balancing bacterial populations and promoting their favorable metabolic action. The microbiota and its respective metabolites communicate to the host through a series of biochemical and functional links thereby affecting host homeostasis and health. In particular, the gastrointestinal tract communicates with the central nervous system through the gut-brain axis to support neuronal development and maintenance while gut dysbiosis manifests in neurological disease. There are three basic mechanisms that mediate the communication between the gut and the brain: direct neuronal communication, endocrine signaling mediators and the immune system. Together, these systems create a highly integrated molecular communication network that link systemic imbalances with the development of neurodegeneration including insulin regulation, fat metabolism, oxidative markers and immune signaling. Age is a common factor in the development of neurodegenerative disease and probiotics prevent many harmful effects of aging such as decreased neurotransmitter levels, chronic inflammation, oxidative stress and apoptosis-all factors that are proven aggravators of neurodegenerative disease. Indeed patients with Parkinson's and Alzheimer's diseases have a high rate of gastrointestinal comorbidities and it has be proposed by some the management of the gut microbiota may prevent or alleviate the symptoms of these chronic diseases.

Bifidobacterium animalis in combination with human origin of Lactobacillus plantarum ameliorate neuroinflammation in experimental model of multiple sclerosis by altering CD4+ T cell subset balance

BACKGROUND

Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). Recent reports have shown that probiotics can induce immunomodulatory activity with promising effects in inflammatory diseases. This study was designed to reveal the molecular and cellular mechanisms underlying the effect of Lactobacillus plantarum A7, which comprises human commensal bacteria, and Bifidobacterium animalis, a potential probiotic strain, on alleviation of experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

METHODS

To evaluate the therapeutic effects of probiotic strains, female C57BL/6 mice (8-10 wks old) received Lactobacillus plantarum A7, Bifidobacterium animalis PTCC 1631or a mixture of both strains through oral administration daily for 22days beginning simultaneous with induction of EAE. The clinical parameters were recorded daily. On Day 22, each mouse was bled, and their spinal cord was removed for histology analysis. The effects of the treatments on regulatory T (Treg) cells level were evaluated using flow cytometry, and T-cell proliferation was assessed using a BrdU incorporation assay. The supernatants of spleen and lymph nodes cultured and mononuclear cells were collected for quantification of different panel of pro and anti-inflammatory cytokines by ELISA. The analysis of gene expression was performed at RNA level for transcription factors by real-time PCR.

RESULTS

The results showed that treatment with a mixture of the two strains caused a more significant delay in the time of disease onset and clinical score compared to when the strains were used alone. The pathological features of the disease, such as mononuclear infiltration into the CNS, were also inhibited more significantly by the combinational approach. The results also revealed that treatment with combination of both strains enhanced the population of CD4⁺CD25⁺Foxp3⁺-expressing T-cells in the lymph nodes and the spleen.

TREATMENT

with our probiotic strains markedly inhibited disease associated cytokines while increased anti-inflammatory cytokines. Additionally, L. plantarumA7 and B. animalis ameliorated EAE condition by favoring Th2 and Treg differentiation via up-regulation of Foxp3 and GATA3 in the brain and spleen as well as inhibited the differentiation of Th1 and Th17 cells.

CONCLUSIONS

The current research provided evidence that probiotic therapy with L. plantarum and B. animalis can effectively attenuate EAE progression as well as reinforce the polarization of regulatory T-cells.

The Gut Microbiota in Immune-Mediated Inflammatory Diseases

The collection of microbes and their genes that exist within and on the human body, collectively known as the microbiome has emerged as a principal factor in human health and disease. Humans and microbes have established a symbiotic association over time, and perturbations in this association have been linked to several immune-mediated inflammatory diseases (IMID) including inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis. IMID is a term used to describe a group of chronic, highly disabling diseases that affect different organ systems. Though a cornerstone commonality between IMID is the idiopathic nature of disease, a considerable portion of their pathobiology overlaps including epidemiological co-occurrence, genetic susceptibility loci and environmental risk factors. At present, it is clear that persons with an IMID are at an increased risk for developing comorbidities, including additional IMID. Advancements in sequencing technologies and a parallel explosion of 16S rDNA and metagenomics community profiling studies have allowed for the characterization of microbiomes throughout the human body including the gut, in a myriad of human diseases and in health. The main challenge now is to determine if alterations of gut flora are common between IMID or, if particular changes in the gut community are in fact specific to a single disease. Herein, we review and discuss the relationships between the gut microbiota and IMID.

The role of microbiome in central nervous system disorders

Mammals live in a co-evolutionary association with the plethora of microorganisms that reside at a variety of tissue microenvironments. The microbiome represents the collective genomes of these co-existing microorganisms, which is shaped by host factors such as genetics and nutrients but in turn is able to influence host biology in health and disease. Niche-specific microbiome, prominently the gut microbiome, has the capacity to effect both local and distal sites within the host. The gut microbiome has played a crucial role in the bidirectional gut-brain axis that integrates the gut and central nervous system (CNS) activities, and thus the concept of microbiome-gut-brain axis is emerging. Studies are revealing how diverse forms of neuro-immune and neuro-psychiatric disorders are correlated with or modulated by variations of microbiome, microbiota-derived products and exogenous antibiotics and probiotics. The microbiome poises the peripheral immune homeostasis and predisposes host susceptibility to CNS autoimmune diseases such as multiple sclerosis. Neural, endocrine and metabolic mechanisms are also critical mediators of the microbiome-CNS signaling, which are more involved in neuro-psychiatric disorders such as autism, depression, anxiety, stress. Research on the role of microbiome in CNS disorders deepens our academic knowledge about host-microbiome commensalism in central regulation and in practicality, holds conceivable promise for developing novel prognostic and therapeutic avenues for CNS disorders.

Isolation and structural identification of glycopolymers of Bifidobacterium bifidum BIM B-733D as putative players in pathogenesis of autoimmune thyroid diseases

Bifidobacterium bifidum 791 (commercially available as B. bifidum BIM B-733D) cell-surface biopolymers (BPs) interact selectively with human serum thyroid peroxidase (TPO) and thyroglobulin (Tg) autoantibodies (anti TPO and anti Tg, respectively). BPanti-TPO and BPanti-Tg were isolated from the soluble fraction of B. bifidum BIM B-733D by affinity chromatography with anti-TPO or anti-Tg, respectively. Homogeneity of affinity eluates (AEanti-TPO and AEanti-Tg) was tested by size exclusion chromatography. For each AE, the elution profiles generated on the basis of absorbance at 280 nm do not conform to ELISA data for functional activity characteristic of BPs. Moreover, high functional activity was detected in chromatographic fractions that had significantly different molecular weights and no absorbance at 280 nm, which suggests a non-protein (carbohydrate) nature of BPanti-TPO and BPanti-Tg. The semi-preparative size exclusion chromatography of AEanti-TPO and AEanti-Tg with detection by refractometer gave 5,000-7,000 Da fractions containing substances that interact selectively with either anti TPO (BPanti-TPO) or anti-Tg (BPanti-Tg) according to ELISA data. Analysis by two-dimensional NMR spectroscopy including a 1H, 13C-heteronuclear single-quantum coherence experiment indicated that both substances are linear α-1,6-glucans. For the first time, an immunological similarity (molecular mimicry) of glycopolymers of B. bifidum BIM B-733D and human thyroid proteins, TPO and Tg, was shown. On the whole, our data point to a possible role of bifidobacteria in the pathogenesis of autoimmune thyroid diseases (ATD). The main requirements for triggering/acceleration or prevention/abrogation of ATD by bifidobacteria through molecular mimicry mechanism are hypothesised to be (1) genetic predisposition to ATD and (2) intestinal epithelium penetration by α-1,6-glucan.

Amelioration of experimental autoimmune encephalomyelitis by probiotic mixture is mediated by a shift in T helper cell immune response

The immunomodulatory effect of probiotics has been shown mainly in gastro-intestinal immune disorders and little information is available on the inflammation of central nervous system. Recently we reported that IRT5 probiotics, a mixture of 5 probiotics, could suppress diverse experimental inflammatory disorders. In this study, we evaluated the prophylactic and therapeutic effects of IRT5 probiotics in experimental autoimmune encephalomyelitis (EAE), a T cell mediated inflammatory autoimmune disease of the central nervous system. Pretreatment of IRT5 probiotics before disease induction significantly suppressed EAE development. In addition, treatment with IRT5 probiotics to the ongoing EAE delayed the disease onset. Administration of IRT5 probiotics inhibited the pro-inflammatory Th1/Th17 polarization, while inducing IL10(+) producing or/and Foxp3(+) regulatory T cells, both in the peripheral immune system and at the site of inflammation. Collectively, our data suggest that IRT5 probiotics could be applicable to modulate T cell mediated neuronal autoimmune diseases, including multiple sclerosis.

The influence of nutritional factors on the prognosis of multiple sclerosis

The effect of nutrition and dietary supplements on the course of multiple sclerosis (MS) is a topic of great interest to both patients and clinicians. In particular, vitamin D status has been shown to influence both the incidence and the course of MS. High vitamin D levels are probably protective against the development of MS, although the efficacy of vitamin D supplementation in slowing progression of MS remains to be established. The influence of polyunsaturated fatty acids (PUFAs) on the development and course of MS has also long been under investigation. Small clinical trials suggest a modest reduction in the severity and duration of relapses in patients with MS receiving PUFA supplements. Other nutritional factors have been evaluated for their effect on MS disease progression, including milk proteins, gluten, probiotics, antioxidants (uric acid, vitamins A, C and E, lipoic acid), polyphenols, Ginkgo biloba extracts and curcumin. However, further studies are needed to evaluate the effects of these dietary components on the relapse rate and progression of MS. This Review gives an overview of the literature on the nutritional factors most commonly implicated as having an effect on MS and discusses the biological rationale that is thought to underlie their influence.

Influence of dietary components on regulatory T cells

Common dietary components including vitamins A and D, omega-3 and probiotics are now widely accepted to be essential to protect against many diseases with an inflammatory nature. On the other hand, high-fat diets are documented to exert multiple deleterious effects, including fatty liver diseases. Here we discuss the effect of dietary components on regulatory T cell (Treg) homeostasis, a central element of the immune system to prevent chronic tissue inflammation. Accordingly, evidence on the impact of dietary components on diseases in which Tregs play an influential role will be discussed. We will review chronic tissue-specific autoimmune and inflammatory conditions such as inflammatory bowel disease, type 1 diabetes mellitus, multiple sclerosis, rheumatoid arthritis and allergies among chronic diseases where dietary factors could have a direct influence via modulation of Tregs homeostasis and functions.

Neurogenic bowel dysfunction in patients with spinal cord injury, myelomeningocele, multiple sclerosis and Parkinson’s disease

Exciting new features have been described concerning neurogenic bowel dysfunction, including interactions between the central nervous system, the enteric nervous system, axonal injury, neuronal loss, neurotransmission of noxious and non-noxious stimuli, and the fields of gastroenterology and neurology. Patients with spinal cord injury, myelomeningocele, multiple sclerosis and Parkinson’s disease present with serious upper and lower bowel dysfunctions characterized by constipation, incontinence, gastrointestinal motor dysfunction and altered visceral sensitivity. Spinal cord injury is associated with severe autonomic dysfunction, and bowel dysfunction is a major physical and psychological burden for these patients. An adult myelomeningocele patient commonly has multiple problems reflecting the multisystemic nature of the disease. Multiple sclerosis is a neurodegenerative disorder in which axonal injury, neuronal loss, and atrophy of the central nervous system can lead to permanent neurological damage and clinical disability. Parkinson's disease is a multisystem disorder involving dopaminergic, noradrenergic, serotoninergic and cholinergic systems, characterized by motor and non-motor symptoms. Parkinson's disease affects several neuronal structures outside the substantia nigra, among which is the enteric nervous system. Recent reports have shown that the lesions in the enteric nervous system occur in very early stages of the disease, even before the involvement of the central nervous system. This has led to the postulation that the enteric nervous system could be critical in the pathophysiology of Parkinson's disease, as it could represent the point of entry for a putative environmental factor to initiate the pathological process. This review covers the data related to the etiology, epidemiology, clinical expression, pathophysiology, genetic aspects, gastrointestinal motor dysfunction, visceral sensitivity, management, prevention and prognosis of neurogenic bowel dysfunction patients with these neurological diseases. Embryological, morphological and experimental studies on animal models and humans are also taken into account.

The lactic acid bacterium Pediococcus acidilactici suppresses autoimmune encephalomyelitis by inducing IL-10-producing regulatory T cells

Background

Certain intestinal microflora are thought to regulate the systemic immune response. Lactic acid bacteria are one of the most studied bacteria in terms of their beneficial effects on health and autoimmune diseases; one of which is Multiple sclerosis (MS) which affects the central nervous system. We investigated whether the lactic acid bacterium Pediococcus acidilactici, which comprises human commensal bacteria, has beneficial effects on experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

Methodology/Principal Findings

P. acidilactici R037 was orally administered to EAE mice to investigate the effects of R037. R037 treatment suppressed clinical EAE severity as prophylaxis and therapy. The antigen-specific production of inflammatory cytokines was inhibited in R037-treated mice. A significant increase in the number of CD4⁺ Interleukin (IL)-10-producing cells was observed in the mesenteric lymph nodes (MLNs) and spleens isolated from R037-treated naive mice, while no increase was observed in the number of these cells in the lamina propria. Because only a slight increase in the CD4⁺Foxp3⁺ cells was observed in MLNs, R037 may primarily induce Foxp3⁻ IL10-producing T regulatory type 1 (Tr1) cells in MLNs, which contribute to the beneficial effect of R037 on EAE.

Conclusions/Significance

An orally administered single strain of P. acidilactici R037 ameliorates EAE by inducing IL10-producing Tr1 cells. Our findings indicate the therapeutic potential of the oral administration of R037 for treating multiple sclerosis.

Comparative effects of six probiotic strains on immune function in vitro

There is considerable interest in the strain specificity of immune modulation by probiotics. The present study compared the immunomodulatory properties of six probiotic strains of different species and two genera in a human peripheral blood mononuclear cell (PBMC) model in vitro. Live cells of lactobacilli (Lactobacillus casei Shirota, L. rhamnosus GG, L. plantarum NCIMB 8826 and L. reuteri NCIMB 11951) and bifidobacteria (Bifidobacterium longum SP 07/3 and B. bifidum MF 20/5) were individually incubated with PBMC from seven healthy subjects for 24 h. Probiotic strains increased the proportion of CD69+ on lymphocytes, T cells, T cell subsets and natural killer (NK) cells, and increased the proportion of CD25+, mainly on lymphocytes and NK cells. The effects on activation marker expression did not appear to be strain specific. NK cell activity was significantly increased by all six strains, without any significant difference between strains. Probiotic strains increased production of IL-1β, IL-6, IL-10, TNF-α, granulocyte-macrophage colony-stimulating factor and macrophage inflammatory protein 1α to different extents, but had no effect on the production of IL-2, IL-4, IL-5 or TNF-β. The cytokines that showed strain-specific modulation included IL-10, interferon-γ, TNF-α, IL-12p70, IL-6 and monocyte chemotactic protein-1. The Lactobacillus strains tended to promote T helper 1 cytokines, whereas bifidobacterial strains tended to produce a more anti-inflammatory profile. The results suggest that there was limited evidence of strain-specific effects of probiotics with respect to T cell and NK cell activation or NK cell activity, whereas production of some cytokines was differentially influenced by probiotic strains.

Probiotic upregulation of peripheral IL-17 responses does not exacerbate neurological symptoms in experimental autoimmune encephalomyelitis mouse models

CONTEXT

It is of great importance to evaluate the safety of probiotics in dysregulated immune conditions, as probiotics can possibly modulate immune functions in the host.

OBJECTIVE

We tried to confirm the safety of using Lactobacillus casei strain Shirota (LcS) to help prevent autoimmunity in the central nervous system.

METHODS

We used two chronic experimental autoimmune encephalomyelitis (EAE) models, a relapse and remission type EAE model in SJL/J mice and a durable type model in C57BL/6 mice. LcS was administered from 1 week before antigen sensitization until the end of the experiments, and neurological symptoms and histopathological changes of the spinal cord were observed. Immunological parameters were also examined in the SJL/J mouse model.

RESULTS

LcS administration did not exacerbate neurological symptoms or histopathological changes of the spinal cord in either model but instead tended to improve neurological symptoms in the SJL/J mouse EAE model. LcS administration transiently upregulated IL-17 production by antigen-stimulated lymphocytes of draining lymph nodes 7 days after sensitization. Enhanced production of IL-10 and an increase in the percentage of CD4(+)CD25(+) T regulatory cells were also observed at the same sites. Strong expression of IL-17 mRNA was detected in the spinal cord of mice that displayed severe neurological symptoms on day 12, but this expression was not enhanced by LcS administration.

CONCLUSION

These results demonstrate that LcS does not exacerbate, but instead may improve EAE depending on the immunization conditions, and that IL-17 responses at peripheral sites may not always result in a worsening of autoimmune diseases.