Preventive Effect of Lactobacillus helveticus SBT2171 on Collagen-Induced Arthritis in Mice

Food safety assessment and 28-day toxicity study of the synbiotic medical food consortium SBD121

The human gut microbiome plays a crucial role in immune function. The synbiotic consortium or Defined Microbial Assemblage™ (DMA™) Medical Food product, SBD121, consisting of probiotic microbes and prebiotic fibers was designed for the clinical dietary management of rheumatoid arthritis. A 28-day repeated administration study was performed to evaluate the oral toxicity of SBD121 in male and female rats (age/weight at study start: 60 days/156-264 g) administered levels of 0, 4.96 x 1010, 2.48 x 1011, or 4.96 x 1011 colony forming units (CFU)/kg-bw. No treatment related changes were observed in ophthalmological effects, mortality, morbidity, general health and clinical observations, urinalysis, hematology, serum chemistry, absolute or relative organ weights, gross necropsy, or histopathology. A significant decrease in body weight was reported in females in the low and high-concentration groups, which corresponded in part with a significant decrease in food consumption. Results of the functional observation battery indicated front grip strength was significantly greater in the high-concentration males compared to the controls; however, this effect was not considered adverse. Based on these findings, the administration of the Medical Food SBD121 to male and female rats has a no-observable adverse effect level (NOAEL) at the highest level tested of 4.96 x 1011 CFU/kg-bw.

Exploring the significance of microbiota metabolites in rheumatoid arthritis: uncovering their contribution from disease development to biomarker potential

Rheumatoid arthritis (RA) is a multifaceted autoimmune disorder characterized by chronic inflammation and joint destruction. Recent research has elucidated the intricate interplay between gut microbiota and RA pathogenesis, underscoring the role of microbiota-derived metabolites as pivotal contributors to disease development and progression. The human gut microbiota, comprising a vast array of microorganisms and their metabolic byproducts, plays a crucial role in maintaining immune homeostasis. Dysbiosis of this microbial community has been linked to numerous autoimmune disorders, including RA. Microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), tryptophan derivatives, Trimethylamine-N-oxide (TMAO), bile acids, peptidoglycan, and lipopolysaccharide (LPS), exhibit immunomodulatory properties that can either exacerbate or ameliorate inflammation in RA. Mechanistically, these metabolites influence immune cell differentiation, cytokine production, and gut barrier integrity, collectively shaping the autoimmune milieu. This review highlights recent advances in understanding the intricate crosstalk between microbiota metabolites and RA pathogenesis and also discusses the potential of specific metabolites to trigger or suppress autoimmunity, shedding light on their molecular interactions with immune cells and signaling pathways. Additionally, this review explores the translational aspects of microbiota metabolites as diagnostic and prognostic tools in RA. Furthermore, the challenges and prospects of translating these findings into clinical practice are critically examined.

The role of microbiota on rheumatoid arthritis onset

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and pain, which can lead to the loss of normal joint function. Although the exact cause of the disease is not yet fully understood, both environmental factors and genetics may play a role in its development. Moreover, research suggests microbiota contributes to the onset and progression of RA. People with RA show higher quantities of bacteria such as Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella copri, Proteus mirabilis, and Lactobacillus salivarius compared to healthy individuals. Conversely, studies propose that Lactobacillus casei, a probiotic bacterium with immunomodulatory properties, has beneficial effects for RA in murine and human models. Therefore, this work reviews the potential role of the gut microbiota in the development of RA and explores the feasibility of using probiotic bacteria as a supplementary treatment for this disease.

Microbial Imbalance and Intestinal Permeability in the Pathogenesis of Rheumatoid Arthritis: A Mechanism Review with a Focus on Bacterial Translocation, Citrullination, and Probiotic Intervention

This review aims to investigate the role of intestinal permeability (IP) in rheumatoid arthritis (RA), following the hypotheses that leakage of intestinal microbes can influence increased citrullination of peptides leading to anti-citrullinated protein antibody (ACPA) production and inflammation in RA; and that leaked microbes can migrate to the peripheral joints, leading to immune responses and synovitis in peripheral joints. This review explored the evidence for the link between microbial dysbiosis and increased IP in the inflammatory state in RA, as well as the role of increased citrullination and bacterial translocation in the link between microbiota and immune responses in RA. Furthermore, this research aims to evaluate the potential effect of probiotics on RA symptoms and pathogenesis via proposed mechanisms, including the support of microbial balance and suppression of inflammatory factors in RA. A systematic literature search was conducted in three tranches (review, mechanism, intervention). 71 peer-reviewed papers met the inclusions criteria and are summarized in a narrative analysis. Primary studies were critically appraised, synthesized and their relevance to clinical practice evaluated. Evidence found in this mechanism review consistently supported intestinal dysbiosis and increased IP in arthritis. An altered intestinal microbiome was demonstrated in RA with specific microbes such as Collinsella and Eggerthella correlating with increased IP, mucosal inflammation, and immune responses. Hypercitrullination and ACPA production correlated with arthritic symptoms and intestinal microbes were shown to influence hypercitrullination. Some in vitro and animal studies demonstrated a link between leakage of microbes and bacterial translocation, but further research is needed to elucidate the link between IP and citrullination. Probiotic intervention studies evidenced reductions in inflammatory markers IL-6 and TNFα, associated with proliferation of synovial tissue and pain perception in RA joint inflammation. Despite some conflict in the literature, probiotics may present a promising nutritional intervention in the suppression of both, disease activity and inflammatory markers.Key teaching pointsThere is evidence for a dysbiotic profile of the RA gut with specific RA-associated microbes.Increased intestinal permeability and leakage of PAD enzyme facilitates citrullination of peptides.Hypercitrullination and ACPA production correlate to arthritic signs.Microbial leakage and translocation plays a role in the pathogenesis of RA.Probiotics (e.g. L. Casei 01) may reduce inflammation and ameliorate RA symptoms.

Immunomodulatory functions of microorganisms in tissue regenerative healing

External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a crucial regulatory role in this process. This review summarises our current understanding of microorganism-immune system interactions, with a focus on how these interactions impact the renewal and repair ability of tissues, including skin, bone, gut, liver, and nerves. This review concludes with a discussion of the mechanisms by which microbes act on various types of immune cells to affect tissue regeneration, offers potential strategies for using microbial therapies to enhance the regenerative repair function of tissues, and suggest novel therapeutic approaches for regenerative medicine. STATEMENT OF SIGNIFICANCE: Microbiological communities have crucial impacts on human health and illness by participating in energy collection and storage and performing various metabolic processes. External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a critical regulatory role in this process. This study reviews the important correlation between microorganisms and the immune system and investigates the mechanism of various microorganism that participate in the regeneration and repair of tissues and organs by modulating immune system.

Gut microbiota in pre-clinical rheumatoid arthritis: From pathogenesis to preventing progression

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive polyarthritis that leads to cartilage and bone damage. Pre-clinical RA is a prolonged state before clinical arthritis and RA develop, in which autoantibodies (antibodies against citrullinated proteins, rheumatoid factors) can be present due to the breakdown of immunologic self-tolerance. As early treatment initiation before the onset of polyarthritis may achieve sustained remission, optimize clinical outcomes, and even prevent RA progression, the pre-clinical RA stage is showing the prospect to be the window of opportunity for RA treatment. Growing evidence has shown the role of the gut microbiota in inducing systemic inflammation and polyarthritis via multiple mechanisms, which may involve molecular mimicry, impaired intestinal barrier function, gut microbiota-derived metabolites mediated immune regulation, modulation of the gut microbiota's effect on immune cells, intestinal epithelial cells autophagy, and the interaction between the microbiome and human leukocyte antigen alleles as well as microRNAs. Since gut microbiota alterations in pre-clinical RA have been reported, potential therapies for modifying the gut microbiota in pre-clinical RA, including natural products, antibiotic therapy, fecal microbiota transplantation, probiotics, microRNAs therapy, vitamin D supplementation, autophagy inducer-based treatment, prebiotics, and diet, holds great promise for the successful treatment and even prevention of RA via altering ongoing inflammation. In this review, we summarized current studies that include pathogenesis of gut microbiota in RA progression and promising therapeutic strategies to provide novel ideas for the management of pre-clinical RA and possibly preventing arthritis progression.

Gut-Joint Axis: Impact of Bifidobacterial Cell Wall Lipoproteins on Arthritis Development

Gut microbiota affect progression of rheumatoid arthritis (RA). The present study aims at investigating the protective potential of Bifidobacterium longum cell wall lipoproteins (Lpps) shown to modulate the intestinal microbiome and prevent osteoarthritis. Arthritis was induced by collagen (CIA) or anti-collagen antibodies (CAIA) injection. Intake of 0.5 mg of Lpps/L, but not 0.25 and 1 mg of Lpps/L, significantly alleviated RA symptoms in CIA DBA/1OOaHsd mice. The arthritis index (AI) was also reduced in CAIA mice. In the CIA-protected group, colon Ligilactobacillus murinus, caecal Lactobacillus johnsonii and spleen weight correlated with AI, whereas the reverse was observed with splenic CD11c+ dendritic cells (cDCs). The unprotected CIA Lpps group harbored higher cecal and colon E. coli and lower caecal L. murinus. Lpps administration to CAIA mice after arthritis induction led to lower colon E. plexicaudatum counts. Splenocytes from CIA-protected mice triggered by LPS secreted higher Il-10 than control ones. However, a higher IL-10 response was not elicited in gnotobiotic RA mice splenocytes with lower cDCs' recruitment. Labeled bacteria with the Lpps signal were detected in CIA mice bone marrow (BM) cDCs 5 and 16 h post-gavage but not in Peyer's patches and the spleen. In vitro uptake of Lpps by primary BM and thymus cells was observed within 24 h. An FACS analysis detected the Lpps signal in the plasmacytoid cell compartment but not in cDCs. In conclusion, Lpps dosing is critical for preventing arthritis progression and appropriately modulating the microbiome. Our results also highlight the possible triggering of the immune system by Lpps.

Effect of Motiflor AS probiotic for oral health on cell viability in human gingival fibroblasts and human dental pulp stem cells

Objectives

In this study, it was aimed to investigate the possible effects of oral chewable probiotic tablets (PTs) produced to directly support the oral flora on the proliferation of human dental pulp stem cells (DPSCs) and human gingival fibroblast cells (HGFCs).

Materials and Methods

For analysis in this study, "Motiflor AS," a PT that dissolves in the mouth, containing 13.5mg Lactobacillus helveticus Rosell-52, L. rhamnosus Rosell-11, L. halivarus HA-118, and Bifidobacterium longum Rosell-175 was used. Cell survival and proliferation were analyzed by methyl-thiazole-diphenyl-tetrazolium (MTT) test and real-time cell analysis method (xCELLigence RTCA-DP) after 24-, 48-, and 72-h incubation periods.

Results

According to the data obtained with RTCA-DP software, there was a significant increase in the proliferation of human dental pulp stem cells (HDPSCs) and HGFCs in the 72-h incubation after PT application compared to the 24-h and 48-h incubations (P < 0.0001). After the MTT test, for HDPSCs, the cell proliferation rate was 62.8% and 85.6% in 24- and 48-h incubation, respectively, while HDPSCs cell proliferation rate in 72-h incubation was 135.2% (P < 0.0001). For HGFCs, the cell proliferation rate was 73% and 120.4% in 24- and 48-h incubation, respectively, while HDPSCs cell proliferation rate in 72-h incubation was 139.8% (P < 0.0001). When the results of the two tests applied were evaluated together, the results showed compatibility.

Conclusions

Based on the results, it has been concluded that PT will be useful for maintaining oral health and for dental and gingival patients who will/have undergone dental treatment. It should be keep in mind that protecting our oral and dental health is very important in terms of protecting our general health.

Effects of Microecological Regulators on Rheumatoid Arthritis: A Systematic Review and Meta-Analysis of Randomized, Controlled Trials

In this study, the available data from published randomized, controlled trials (RCTs) of the use of intestinal microecological regulators as adjuvant therapies to relieve the disease activity of rheumatoid arthritis (RA) are systematically compared. An English literature search was performed using PubMed, Embase, Scopus, Web of Science and the Cochrane Central Registry of Controlled Trials and supplemented by hand searching reference lists. Three independent reviewers screened and assessed the quality of the studies. Among the 2355 citations identified, 12 RCTs were included. All data were pooled using a mean difference (MD) with a 95% CI. The disease activity score (DAS) showed a significant improvement following microecological regulators treatment (MD (95% CI) of -1.01 (-1.81, -0.2)). A borderline significant reduction in the health assessment questionnaire (HAQ) scores was observed (MD (95% CI) of -0.11 (-0.21, -0.02)). We also confirmed the known effects of probiotics on inflammatory parameters such as the C-reactive protein (CRP) (MD -1.78 (95% CI -2.90, -0.66)) and L-1β (MD -7.26 (95% CI -13.03, -1.50)). No significant impact on visual analogue scale (VAS) of pain and erythrocyte sedimentation rate (ESR) reduction was observed. Intestinal microecological regulators supplementation could decrease RA activity with a significant effect on DAS28, HAQ and inflammatory cytokines. Nevertheless, these findings need further confirmation in large clinical studies with greater consideration of the confounding variables of age, disease duration, and individual medication regimens.

Consequences of collagen induced inflammatory arthritis on circadian regulation of the gut microbiome

The gut microbiota is important for host health and immune system function. Moreover autoimmune diseases, such as rheumatoid arthritis, are associated with significant gut microbiota dysbiosis, although the causes and consequences of this are not fully understood. It has become clear that the composition and metabolic outputs of the microbiome exhibit robust 24 h oscillations, a result of daily variation in timing of food intake as well as rhythmic circadian clock function in the gut. Here, we report that experimental inflammatory arthritis leads to a re-organization of circadian rhythmicity in both the gut and associated microbiome. Mice with collagen induced arthritis exhibited extensive changes in rhythmic gene expression in the colon, and reduced barrier integrity. Re-modeling of the host gut circadian transcriptome was accompanied by significant alteration of the microbiota, including widespread loss of rhythmicity in symbiont species of Lactobacillus, and alteration in circulating microbial derived factors, such as tryptophan metabolites, which are associated with maintenance of barrier function and immune cell populations within the gut. These findings highlight that altered circadian rhythmicity during inflammatory disease contributes to dysregulation of gut integrity and microbiome function.

Safety and efficacy of probiotic supplementation in 8 types of inflammatory arthritis: A systematic review and meta-analysis of 34 randomized controlled trials

Objective

To evaluate Safety and efficacy of probiotic supplementation in inflammatory arthritis.

Methods

The literature on the treatment of inflammatory arthritis with probiotics has been collected in databases such as CNKI, Pubmed, Cochrane library, Embase, etc. The search time is for them to build the database until May 2022. The included literatures are randomized controlled trials (RCTs) of probiotics in the treatment of hyperuricemia and gout. The Cochrane risk assessment tool was used for quality evaluation, and the Rev Man5.3 software was used for meta-analysis.

Results

A total of 37 records were finally included, involving 34 RCTs and 8 types of autoimmune disease (Hyperuricemia and gout, Inflammatory bowel disease arthritis, juvenile idiopathic arthritis [JIA], Osteoarthritis [OA], Osteoporosis and Osteopenia, Psoriasis, rheumatoid arthritis (RA), Spondyloarthritis). RA involved 10 RCTs (632 participants) whose results showed that probiotic intervention reduced CRP. Psoriasis involved 4 RCTs (214 participants) whose results showed that probiotic intervention could reduce PASI scores. Spondyloarthritis involved 2 RCTs (197 participants) whose results showed that probiotic intervention improved symptoms in patients. Osteoporosis and Ostepenia involving 10 RCTs (1156 participants) showed that probiotic intervention improved bone mineral density in patients. Hyperuricemia and gout involving 4 RCTs (294 participants) showed that probiotic intervention improved serum uric acid in patients. OA involving 1 RCTs (433 participants) showed that probiotic intervention improved symptoms in patients. JIA involving 2 RCTs (72 participants) showed that probiotic intervention improved symptoms in patients. Inflammatory bowel disease arthritis involving 1 RCTs (120 participants) showed that probiotic intervention improved symptoms in patients. All of the above RCTs showed that probiotics did not increase the incidence of adverse events.

Conclusion

Probiotic supplements may improve Hyperuricemia and gout, Inflammatory bowel disease arthritis, JIA, OA, Osteoporosis and Osteopenia, Psoriasis, RA, Spondyloarthritis. However, more randomized controlled trials are needed in the future to determine the efficacy and optimal dosing design of probiotics.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021286425, identifier CRD42021286425.

Microbiota-assisted therapy for systemic inflammatory arthritis: advances and mechanistic insights

Research on the influence of gut microbiota on systemic inflammatory arthritis has exploded in the past decade. Gut microbiota changes may be a crucial regulatory component in systemic inflammatory arthritis. As a result of advancements in the field, microbiota-assisted therapy has evolved, but this discipline is still in its infancy. Consequently, we review the limitations of current systemic inflammatory arthritis treatment, analyze the connection between the microbiota and arthritis, and summarize the research progress of microbiota regulating systemic inflammatory arthritis and the further development aspects of microbiota-assisted therapy. Finally, the partial mechanisms of microbiota-assisted therapy of systemic inflammatory arthritis are being discussed. In general, this review summarizes the current progress, challenges, and prospects of microbiota-assisted therapy for systemic inflammatory arthritis and points out the direction for the development of microbiota-assisted therapy in the future.

Role of Intestinal Dysbiosis and Nutrition in Rheumatoid Arthritis

Rheumatoid arthritis is a chronic systemic immune-mediated disease caused by genetic and environmental factors. It is often characterized by the generation of autoantibodies that lead to synovial inflammation and eventual multi-joint destruction. A growing number of studies have shown significant differences in the gut microbiota composition of rheumatoid arthritis (RA) patients compared to healthy controls. Environmental factors, and changes in diet and nutrition are thought to play a role in developing this dysbiosis. This review aims to summarize the current knowledge of intestinal dysbiosis, the role of nutritional factors, and its implications in the pathogenesis of rheumatoid arthritis and autoimmunity. The future direction focuses on developing microbiome manipulation therapeutics for RA disease management.

Lycium barbarum polysaccharide modulates gut microbiota to alleviate rheumatoid arthritis in a rat model

Rheumatoid arthritis (RA) seriously impairs the quality of life of sufferers. It has been shown that Lycium barbarum polysaccharide (LBP), a natural active indigestible ingredient with medicinal and edible functions, can effectively relieve RA, however, whether this effect is related to gut microbiota is not known. This study aimed to explore the RA alleviating mechanism of LBP mediated by gut microbiota using a collagen-induced arthritis rat model. The results showed that LBP significantly changed the gut microflora structure accompanied with the RA alleviation. Specifically, a LBP intervention reduced the relative abundance of Lachnospiraceae_NK4A136_group and uncultured_bacterium_f_Ruminococcaceae and significantly increased the abundance of Romboutsia, Lactobacillus, Dubosiella and Faecalibaculum. The mRNA contents of several colonic epithelial genes including Dpep3, Gstm6, Slc27a2, Col11a2, Sycp2, SNORA22, Tnni1, Gpnmb, Mypn and Acsl6, which are potentially associated to RA, were down-regulated due to the DNA hypermethylation, possibly caused by the elevating content of a bacterial metabolite S-adenosyl methionine (SAM). In conclusion, our current study suggests that LBP alleviated RA by reshaping the composition of intestinal microflora which may generate SAM, inducing DNA hypermethylation of RA-related genes in the host intestinal epithelium and subsequently reducing their expression.

Lactobacillus helveticus Prevents Periodontitis Induced by Aggregatibacter actinomycetemcomitans in Rats by Regulating β-Defensins

Objective

To study the preventive effect of Lactobacillus helveticus (L. helveticus) on periodontitis induced by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in rats.

Methods

Eighteen 8-week-old female rats were randomly divided into three groups: Sham group, Trehalose group, and L. helveticus SBT2171 (LH2171) group. We measured the distance of the cementoenamel junction-alveolar bone crest (CEJ-ABC) to evaluate alveolar bone resorption. Hematoxylin-eosin staining was used to observe the histopathological changes of rat hemimaxillary tissues. We detected the expression of β-defensins, tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β, and IL-6 and the number of A. actinomycetemcomitans in rat gingival tissues by quantitative reverse transcriptase polymerase chain reaction. The levels of IL-1β, IL-6, and TNF-α in rat gingival tissues were also measured by enzyme-linked immunosorbent assay.

Results

Compared with the Trehalose group, the distance of CEJ-ABC was prominently reduced and alveolar bone resorption was notably improved in the LH2171 group. And the infiltration of inflammatory cells in the hemimaxillary tissue decreased obviously, periodontal fibers were arranged neatly, connective tissue small blood vessels proliferated, and the number of A. actinomycetemcomitans reduced significantly in the LH2171 group. In addition, the mRNA expression and release of inflammatory factors in the gingival tissues in the LH2171 group were notably lower than those in the Trehalose group. On the 21st and 36th day, the expression of β-defensins in the gingival tissue of the LH2171 group increased significantly.

Conclusion

L. helveticus improves alveolar bone resorption and increases the expression of β-defensins thereby inhibiting the number of A. actinomycetemcomitans and thus prevents periodontitis.

Propionibacterium freudenreichii Inhibits RANKL-Induced Osteoclast Differentiation and Ameliorates Rheumatoid Arthritis in Collagen-Induced Arthritis Mice

Osteoclast differentiation is crucial for bone absorption, and osteoclasts are involved in bone destruction in rheumatoid arthritis (RA). Dairy Propionibacterium freudenreichii is used as a cheese starter and possesses prebiotic and postbiotic properties. It is known to stimulate the growth of bifidobacteria and produces valuable metabolites, such as vitamin B12 and propionic acid. However, limited information is available on the beneficial effects of P. freudenreichii on human disease. Herein, we aimed to investigate the inhibitory effect of P. freudenreichii MJ2 (MJ2) isolated from raw milk on osteoclast differentiation and evaluate the improvement in RA. The murine macrophage cell line, RAW 264.7, and a collagen-induced arthritis (CIA) mouse model were used to perform in vitro and in vivo studies, respectively. Heat-killed P. freudenreichii MJ2 (hkMJ2)-treated cells significantly inhibited RANKL-induced osteoclast differentiation and TRAP activity. HkMJ2-treated cells exhibited significantly decreased expression of genes and proteins related to RANKL-induced osteoclast differentiation. MJ2 administration decreased the arthritic score in the CIA mouse model. Live and dead MJ2 inhibited bone loss and afforded protection against bone erosion and joint damage in CIA mice. MJ2 decreased the levels of collagen-specific antibodies and inflammatory cytokines and the expression of osteoclast differentiation-related genes and proteins in CIA mice. Interestingly, live and dead MJ2 showed similar RA improvement effects in CIA mice. In conclusion, P. freudenreichii MJ2 inhibited osteoclast differentiation by inhibiting the NF-κB signaling pathway and ameliorated CIA.

Therapeutic Potential of a Novel Bifidobacterium Identified Through Microbiome Profiling of RA Patients With Different RF Levels

The potential therapeutic effects of probiotic bacteria in rheumatoid arthritis (RA) remain controversial. Thus, this study aimed to discover potential therapeutic bacteria based on the relationship between the gut microbiome and rheumatoid factor (RF) in RA. Bacterial genomic DNA was extracted from the fecal samples of 93 RA patients and 16 healthy subjects. Microbiota profiling was conducted through 16S rRNA sequencing and bioinformatics analyses. The effects of Bifidobacterium strains on human peripheral blood mononuclear cells and collagen-induced arthritis (CIA) mice were assessed. Significant differences in gut microbiota composition were observed in patients with different RF levels. The relative abundance of Bifidobacterium and Collinsella was lower in RF-high than in RF-low and RF-negative RA patients, while the relative abundance of Clostridium of Ruminococcaceae family was higher in RF-high than in RF-low and RF-negative patients. Among 10 differentially abundant Bifidobacterium, B. longum RAPO exhibited the strongest ability to inhibit IL-17 secretion. Oral administration of B. longum RAPO in CIA mice, obese CIA, and humanized avatar model significantly reduced RA incidence, arthritis score, inflammation, bone damage, cartilage damage, Th17 cells, and inflammatory cytokine secretion. Additionally, B. longum RAPO significantly inhibited Th17 cells and Th17-related genes—IL-17A, IRF4, RORC, IL-21, and IL-23R—in the PBMCs of rheumatoid arthritis patients. Our findings suggest that B. longum RAPO may alleviate RA by inhibiting the production of IL-17 and other proinflammatory mediators. The safety and efficacy of B. longum RAPO in patients with RA and other autoimmune disorders merit further investigation.

Lactiplantibacillus plantarum HG20 attenuates II type collagen-induced rheumatoid arthritis in rats via anti-inflammatory and inhibition of apoptosis

AIMS

This study aimed to explore the therapeutic effects of Lactiplantibacillus plantarum HG20 (HG20) on collagen-induced arthritis (CIA) rats and its mechanism.

METHODS AND RESULTS

CIA rats were established by injecting bovine type II collagen for 7 days, and treated by intragastric administration HG20 for 21 days. The foot palm temperature and arthritis score were measured once a week. The pathological changes in the knee joint were observed by hematoxylin and eosin staining. The levels of cytokines were detected by enzyme linked immunosorbent assay, and the effects of HG20 on inflammatory and apoptosis pathway of spleen cells were detected by western blot analysis. The results indicated that HG20 reduced the joint swelling degree and foot palm temperature, inhibited the development of joint histopathology, decreased the levels of pro-inflammatory cytokines, down-regulate the expression of pro-inflammatory cytokines by nuclear factor kappa-B pathway, and inhibited the apoptosis of spleen cells by inhibiting phosphatidylinositol 3-kinase/protein kinase B pathway and regulating apoptosis pathways.

CONCLUSIONS

HG20 had an adjuvant therapeutic effect on arthritis in CIA rats, and its mechanism might be related to the inflammatory and apoptosis pathway.

SIGNIFICANCE AND IMPACT OF STUDY

These results revealed that HG20 could be used as a functional probiotic in the field of food and medical, and which played a potential role in the prevention and treatment of arthritis.

Gut microbiota mediated the therapeutic efficacies and the side effects of prednisone in the treatment of MRL/lpr mice

Background

Growing evidences indicate that the alterations in gut microbiota are associated with the efficacy of glucocorticoids (GCs) in the treatment of systemic lupus erythematosus (SLE). However, there is no evidence to prove whether gut microbiota directly mediates the effects of GCs.

Methods

Using the MRL/lpr mice, this study firstly addressed the effects of three doses of prednisone on gut microbiota. Then, this study used fecal microbiota transplantation (FMT) to transfer the gut microbiota of prednisone-treated MRL/lpr mice into the blank MRL/lpr mice to reveal whether the gut microbiota regulated by prednisone had similar therapeutic efficiency and side effects as prednisone.

Results

The effects of prednisone on gut microbiota were dose-dependent in the treatment of MRL/lpr mice. After transplantation into MRL/lpr mice, prednisone-regulated gut microbiota could alleviate lupus, which might be due to decreasing Ruminococcus and Alistipes and retaining the abundance of Lactobacillus. However, prednisone-regulated gut microbiota did not exhibit side effects as prednisone. The reason might be that the pathogens upregulated by prednisone could not survive in the MRL/lpr mice as exogenous microbiota, such as Parasutterella, Parabacteroides, and Escherichia-Shigella.

Conclusions

These data demonstrated that the transplantation of gut microbiota may be an effective method to obtain the therapeutic effects of GCs and avoid the side effects of GCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02620-w.

Lactobacillus rhamnosus Affects Rat Peritoneal Cavity Cell Response to Stimulation with Gut Microbiota: Focus on the Host Innate Immunity

Gut microbiota contribute to shaping the immune repertoire of the host, whereas probiotics may exert beneficial effects by modulating immune responses. Having in mind the differences in both the composition of gut microbiota and the immune response between rats of Albino Oxford (AO) and Dark Agouti (DA) rat strains, we investigated if intraperitoneal (i.p.) injection of live Lactobacillus rhamnosus (LB) may influence peritoneal cavity cell response to in vitro treatments with selected microbiota in the rat strain-dependent manner. Peritoneal cavity cells from AO and DA rats were lavaged two (d2) and seven days (d7) following i.p. injection with LB and tested for NO, urea, and H₂O₂ release basally, or upon in vitro stimulation with autologous E.coli and Enterococcus spp. Whereas the single i.p. injection of LB nearly depleted resident macrophages and increased the proportion of small inflammatory macrophages and monocytes on d2 in both rat strains, greater proportion of MHCII^hiCD163^- and CCR7⁺ cells and increased NO/diminished H₂O₂ release in DA compared with AO rats suggest a more intense inflammatory priming by LB in this rat strain. Even though E.coli- and/or Enterococcus spp.-induced rise in H₂O₂ release in vitro was abrogated by LB in cells from both rat strains, LB prevented microbiota-induced increase in NO/urea ratio only in cells from AO and augmented it in cells from DA rats. Thus, the immunomodulatory properties may not be constant for particular probiotic bacteria, but shaped by innate immunity of the host.

Probiotic Supplementation for Rheumatoid Arthritis: A Promising Adjuvant Therapy in the Gut Microbiome Era

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease that ultimately leads to joint destruction and functional disability. Although the exact etiology of RA is not fully understood, it is well established that gut microbiota (GM) plays a vital role in the pathogenesis of RA, with accumulating evidence suggesting that gut dysbiosis induces a chronic inflammatory response that may be linked to disease development. Of interest, patients with RA have significant changes in the intestinal microbiota compared to healthy controls, and several studies have suggested the use of probiotics as a possible adjuvant therapy for RA. Benefits of probiotic supplementation were reported in animal models of arthritis and human studies, but the current evidence regarding the effect of probiotic supplementation in the management of RA remains insufficient to make definite recommendations. Several different strains of Lactobacillus and Bifidobacteria, as single species or in mixed culture, have been investigated, and some have demonstrated beneficial effects on disease activity in RA human subjects. As of now, L.casei probiotic bacteria seems to be the strongest candidate for application as adjuvant therapy for RA patients. In this review, we highlight the role of GM in the development and progression of RA and summarize the current knowledge on the use of probiotics as a potential adjuvant therapy for RA. We also review the proposed mechanisms whereby probiotics regulate inflammation. Finally, the role of fermented foods is discussed as a possible alternative to probiotic supplements since they have also been reported to have health benefits.

Modification of Gut Microbiota in Inflammatory Arthritis: Highlights and Future Challenges

PURPOSE OF REVIEW

This Review evaluates the available information on the modification of the microbiota by diet, prebiotics, probiotics, or drugs and its association with the severity of arthritis in animals and humans and highlights how this modulation could have therapeutic applications in RA.

RECENT FINDINGS

The gut microbiota and microbiota-derived metabolites play a role in developing rheumatoid arthritis (RA) in animals and humans, making the intestinal microbiota an exciting novel approach to suppress autoimmunity. Studies in animal models of RA show that it is possible to modify the intestinal microbiota with drugs, natural products, diet, probiotics, and prebiotics. Furthermore, these changes showed beneficial effects on symptom relief in animal models of RA and that these effects were associated with modulation of the immune response. Therapies that modify the gut microbiota would significantly impact the preclinical stage of arthritis, based on the fact that dysbiosis occurs before clinical arthritis. The effects of interventions to modulate the microbiota could not reverse arthritis. Furthermore, the therapies modulating therapies in controlling symptoms were limited once arthritis developed. The results obtained in the study of acarbose, probiotics, and prebiotics suggest that these interventions may decrease the disease's incidence rather than treat or cure it.

New Studies of Pathogenesis of Rheumatoid Arthritis with Collagen-Induced and Collagen Antibody-Induced Arthritis Models: New Insight Involving Bacteria Flora

Much public research suggests that autoimmune diseases such as rheumatoid arthritis (RA) are induced by aberrant “self” immune responses attacking autologous tissues and organ components. However, recent studies have reported that autoimmune diseases may be triggered by dysbiotic composition changes of the intestinal bacteria and an imbalance between these bacteria and intestinal immune systems. However, there are a few solid concepts or methods to study the putative involvement and relationship of these inner environmental factors in RA pathogenesis. Fortunately, Collagen-Induced Arthritis (CIA) and Collagen Antibody-Induced Arthritis (CAIA) models have been widely used as animal models for studying the pathogenesis of RA. In addition to RA, these models can be extensively used as animal models for studying complicated hypotheses in many diseases. In this review, we introduce some basic information about the CIA and CAIA models as well as how to apply these models effectively to investigate relationships between the pathogenesis of autoimmune diseases, especially RA, and the dysbiosis of intestinal bacterial flora.

Regional Differences in the Gut Microbiota and Gut-Associated Immunologic Factors in the Ileum and Cecum of Rats With Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation and a multifactorial etiology. We previously showed that gut microbiota dysbiosis in the rat ileum is involved in the development of collagen-induced arthritis (CIA). The gut microbiota in the distinct gastrointestinal tract (GIT) plays region-specific roles, but information on the different roles of the microbiota in distinct GIT compartments of CIA rats is limited. This study aimed to evaluate the region-specific differences in the gut microbial communities and certain gut-associated immunologic factors in the ileum and cecum of CIA rats. Ileal and cecal digesta were collected from CIA and control rats for microbiome analysis. We determined the microbial richness, diversity and taxa as well as the expression of interleukin (IL)-1β and IL-17A in the epithelium and lamina propria of the ileum and cecum mucosal layers. The CIA-induced microbiota alterations in the ileum differed from those in the cecum. The ileal microbiota were more markedly influenced in CIA, as revealed by sharp reductions in the abundances of the families Enterococcaceae, Lactobacillaceae and Streptococcaceae and the genera Lactobacillus and Lactococcus. Moreover, significant increases in IL-1β, and IL-17A mRNA expression were detected in only the ileal epithelium and lamina propria of the mucosal layer. Therefore, the microbial characteristics in the ileum were consistent with the immune-mediated inflammatory features of CIA, suggesting that the ileal microbiota might better represent the CIA-induced inflammatory responses than the cecal microbiota and that these responses might partially impact the progression of RA by regulating intestinal mucosal immunity.

Interactions between Gut Microbiota and Immunomodulatory Cells in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases caused by abnormal immune activation and immune tolerance. Immunomodulatory cells (ICs) play a critical role in the maintenance and homeostasis of normal immune function and in the pathogenesis of RA. The human gastrointestinal tract is inhabited by trillions of commensal microbiota on the mucosal surface that play a fundamental role in the induction, maintenance, and function of the host immune system. Gut microbiota dysbiosis can impact both the local and systemic immune systems and further contribute to various diseases, such as RA. The neighbouring intestinal ICs located in distinct intestinal mucosa may be the most likely intermediary by which the gut microbiota can affect the occurrence and development of RA. However, the reciprocal interaction between the components of the gut microbiota and their microbial metabolites with distinct ICs and how this interaction may impact the development of RA are not well studied. Therefore, a better understanding of the gut microbiota, ICs, and their interactions might improve our knowledge of the mechanisms by which the gut microbiota contribute to RA and facilitate the further development of novel therapeutic approaches. In this review, we have summarized the roles of the gut microbiota in the immunopathogenesis of RA, especially the interactions between the gut microbiota and ICs, and further discussed the strategies for treating RA by targeting/regulating the gut microbiota.

Lactobacillus sakei suppresses collagen-induced arthritis and modulates the differentiation of T helper 17 cells and regulatory B cells

BACKGROUND

To evaluate the immunomodulatory effect of Lactobacillus sakei in a mouse model of rheumatoid arthritis (RA) and in human immune cells.

METHODS

We evaluated whether L. sakei reduced the severity of collagen-induced arthritis (CIA) and modulated interleukin (IL)-17 and IL-10 levels, as well as whether it affected the differentiation of CD4⁺ T cells and regulatory B cells. We evaluated osteoclastogenesis after culturing bone marrow-derived mononuclear cells with L. sakei.

RESULTS

The differentiation of T helper 17 cells and the serum level of IL-17 were suppressed by L. sakei in both human peripheral blood mononuclear cells and mouse splenocytes. The serum level of IL-10 was significantly increased in the L. sakei-treated group, whereas the regulatory T cell population was unchanged. The population of regulatory B cells significantly increased the in L. sakei-treated group. Oral administration of L. sakei reduced the arthritis incidence and score in mice with CIA. Finally, osteoclastogenesis and the mRNA levels of osteoclast-related genes were suppressed in the L. sakei-treated group.

CONCLUSION

L. sakei exerted an anti-inflammatory effect in an animal model of RA, regulated Th17 and regulatory B cell differentiation, and suppressed osteoclastogenesis. Our findings suggest that L. sakei has therapeutic potential for RA.

Protective effects of Bifidobacterium adolescentis on collagen-induced arthritis in rats depend on timing of administration

Emerging studies have addressed the role of probiotics in inflammation modulation via modifying gut microbiota. Perturbed gut microbiota is recognized as a pivotal trigger in the pathogenesis of rheumatoid arthritis (RA), and manipulating gut microbiota at the early phase may be helpful to alleviate the disease based on the fact that dysbiosis occurred prior to clinical arthritis. The current study compared the effects of preventive and therapeutic treatment with Bifidobacterium adolescentis on collagen induced arthritis (CIA) in rats. Early B. adolescentis administration before CIA modelling performed better than late B. adolescentis treatment in reducing the clinical symptoms, rebalancing the pro- and anti-inflammatory responses and maintaining the fecal concentration of short chain fatty acids (SCFAs), as well as restoring the intestinal dysbiosis. Preventive B. adolescentis treatment restored the gut microbiota to a normal level while late B. adolescentis fed rats showed clearly different gut microbial profiles. In addition, there were slight discrepancies between early- and late- treatment of B. adolescentis in the production of specific auto-antibodies and tight junction proteins. All those results highlighted that early treatment of probiotics in arthritis might be a better timing for alleviating arthritis.

The prophylactic effects of different Lactobacilli on collagen-induced arthritis in rats

Recent studies have shed light on the prophylactic effects of Lactobacilli on rheumatoid arthritis (RA). However, the modulatory mechanisms of Lactobacilli remain unclear. The current study evaluated different Lactobacillus species' ability to alleviate arthritis induced by collagen. Rats were intragastrically administered different lactobacilli cocktails two weeks before arthritis induction. The results revealed that the performance of Lactobacillus in relieving arthritis was different for some species. L. reuteri, L. casei, L. rhamnosus and L. fermentum attenuated RA through species-independent pathways that inhibited pro-inflammatory cytokines and anti-CII-antibodies; and through species-dependent immune regulation that was based on rebalancing the intestinal microbiota, and metabolites such as short-chain fatty acids. In particular, L. reuteri and L. casei weaken the Th1 immune response, while L. rhamnosus and L. fermentum impaired Th17 responses. Interestingly, L. plantarum did not alleviate arthritis although it did suppress Th1 and Th17 immune responses, while L. salivarius only delayed the onset of arthritis without influencing the immune response. In conclusion, Lactobacilli protect against collagen-induced-arthritis through both common and individual pathways.

Alteration of the gut microbiota in tumor necrosis factor-α antagonist-treated collagen-induced arthritis mice

AIM

Gut microbiota play an important role in rheumatoid arthritis (RA). Biological therapies targeting tumor necrosis factor-α (TNF-α) have been used for treatment in RA patients. However, whether TNF-α antagonist has some influence on gut microbiota is still unknown. This study aims to investigate the distribution of gut microbiota in collagen-induced arthritis (CIA) mice treated with the TNF-α antagonist etanercept.

METHODS

Collagen-induced arthritis mice were induced by type II collagen. Cytokine expression was detected by real-time polymerase chain reaction. 16S ribosomal RNA sequencing was performed to characterize the gut microbiota in CIA mice treated with vehicle or etanercept. Sequencing reads were processed by Microbial Ecology software program.

RESULTS

Compared with vehicle-treated mice, we showed that CIA mice treated with etanercept led to attenuation of inflammation and reduced expression of TNF-α, interferon (IFN)-γ, interleukin (IL)-6 and IL-21. Meanwhile, results showed operational taxonomic units, richness estimators and the diversity indices of gut microbiota in etanercept-treated mice were lower than that in vehicle-treated mice. Moreover, bacterial abundance analyses showed that genus Escherichia/Shigella was more abundant in etanercept-treated mice, and Lactobacillus, Clostridium XlVa, Tannerella were less abundant. The altered bacterial genus was correlated with TNF-α, IFN-γ, IL-6, IL-21 and IL-10.

CONCLUSION

Our results revealed that TNF-α antagonist treatment can reduce the abundance and diversity of gut microbiota in CIA mice. Targeted gut microbiota may be a new therapeutic strategy for the treatment of RA.

Osteoimmunology: Inflammatory osteolysis and regeneration of the alveolar bone

AIM

Osteoimmunology covers the cellular and molecular mechanisms responsible for inflammatory osteolysis that culminates in the degradation of alveolar bone. Osteoimmunology also focuses on the interplay of immune cells with bone cells during bone remodelling and regeneration. The aim of this review was to provide insights into how osteoimmunology affects alveolar bone health and disease.

METHOD

This review is based on a narrative approach to assemble mouse models that provide insights into the cellular and molecular mechanisms causing inflammatory osteolysis and on the impact of immune cells on alveolar bone regeneration.

RESULTS

Mouse models have revealed the molecular pathways by which microbial and other factors activate immune cells that initiate an inflammatory response. The inflammation-induced alveolar bone loss occurs with the concomitant suppression of bone formation. Mouse models also showed that immune cells contribute to the resolution of inflammation and bone regeneration, even though studies with a focus on alveolar socket healing are rare.

CONCLUSIONS

Considering that osteoimmunology is evolutionarily conserved, osteolysis removes the cause of inflammation by provoking tooth loss. The impact of immune cells on bone regeneration is presumably a way to reinitiate the developmental mechanisms of intramembranous and endochondral bone formation.

Lactobacillus helveticus SBT2171 alleviates allergic symptoms in a murine model for pollen allergy

Lactic acid bacteria are known to have various health-promoting effects and are highly expected to find applications in anti-allergic food materials. In this study, we focused on Lactobacillus helveticus SBT2171 (LH2171), which reportedly modifies some unique immune responses and ameliorated symptoms of patients allergic to mites and house dust in the previous studies. We examined the effect of LH2171 on cytokine production by antigen-stimulated murine naïve splenocytes in vitro and demonstrated that it inhibited IL-4 and IL-13 production while enhancing IFN-γ and IL-10 production. Then, we examined the anti-allergic effect of LH2171 in vivo using a murine model of pollen allergy and found that LH2171 reduced the sneezing frequency when orally administered to mice. We successfully confirmed the immune modulatory activity of LH2171 and its anti-allergic activity against inhaled antigens. These evidences would contribute to identifying the anti-allergic mechanism of LH2171.Abbreviations: ALDH: aldehyde dehydrogenase; EGCG: epigallocatechin gallate; LAB: lactic acid bacteria; LH2171: Lactobacillus helveticus SBT2171; NALT: nasal-associated lymphoid tissue; OVA: ovalbumin.

Lactobacillus helveticus SBT2171 upregulates the expression of β-defensin and ameliorates periodontal disease caused by Porphyromonas gingivalis

Antimicrobial peptides play important roles in the innate immune system of various organisms, and they may also be considered to prevent the organisms from infections. In particular, β-defensins, mainly produced in epithelial cells, are recognized as one of the major antimicrobial peptides in mammals, including humans. In this study, we showed that Lactobacillus helveticus SBT2171 (LH2171), one of the several species of lactic acid bacteria, upregulates the production of β-defensins in oral epithelial cells in vitro. Moreover, LH2171 reduced the increase of proinflammatory cytokine expression, induced by Porphyromonas gingivalis stimulation, in gingival epithelial cells. These data suggested that LH2171 suppresses P. gingivalis-induced inflammation by upregulating the expression of β-defensins in gingival epithelial cells. We subsequently investigated the effects of LH2171 in vivo and revealed that β-defensin expression was increased in the oral cavities of LH2171-fed mice. Furthermore, LH2171 decreased alveolar bone loss, gingival inflammation, and amounts of P. gingivalis-specific 16S ribosomal RNA in the gingiva of P. gingivalis-inoculated mice. Taken together, our results showed that LH2171 upregulates the expression of β-defensins in oral cavity, thereby decreasing the number of P. gingivalis consequently ameliorating the experimental periodontal disease.

Modulation of autoimmune arthritis by environmental 'hygiene' and commensal microbiota

Observations in patients with autoimmune diseases and studies in animal models of autoimmunity have revealed that external environmental factors including exposure to microbes and the state of the host gut microbiota can influence susceptibility to autoimmunity and subsequent disease development. Mechanisms underlying these outcomes continue to be elucidated. These include deviation of the cytokine response and imbalance between pathogenic versus regulatory T cell subsets. Furthermore, specific commensal organisms are associated with enhanced severity of arthritis in susceptible individuals, while exposure to certain microbes or helminths can afford protection against this disease. In addition, the role of metabolites (e.g., short-chain fatty acids, tryptophan catabolites), produced either by the microbes themselves or from their action on dietary products, in modulation of arthritis is increasingly being realized. In this context, re-setting of the microbial dysbiosis in RA using prebiotics, probiotics, or fecal microbial transplant is emerging as a promising approach for the prevention and treatment of arthritis. It is hoped that advances in defining the interplay between gut microbiota, dietary products, and bioactive metabolites would help in the development of therapeutic regimen customized for the needs of individual patients in the near future.

Lactobacillus helveticus SBT2171 Induces A20 Expression via Toll-Like Receptor 2 Signaling and Inhibits the Lipopolysaccharide-Induced Activation of Nuclear Factor-kappa B and Mitogen-Activated Protein Kinases in Peritoneal Macrophages

Lactobacillus helveticus SBT2171 (LH2171) has been reported to ameliorate the development of autoimmune diseases, such as collagen-induced arthritis and experimental autoimmune encephalitis in mice and inhibit interleukin (IL)-6 production in antigen-presenting cells in vitro. Regulation of cytokine production by antigen-presenting cells might be critical for the anti-inflammatory function of LH2171 in autoimmune diseases. However, the mechanism and contributing components of LH2171-mediated inhibition of IL-6 production are unclear. Here, we examined the anti-inflammatory effects of LH2171 in lipopolysaccharide (LPS)-stimulated peritoneal macrophages, as a model of antigen-presenting cells, necessary for the pathogenesis of autoimmune diseases. LH2171 significantly reduced LPS-induced expression and secretion of IL-6 and IL-1β cytokines. It also inhibited activation of nuclear factor-kappa B and mitogen-activated protein kinases (NF-κB/MAPKs). Moreover, LH2171 induced gene expression of several negative regulators of NF-κB/MAPKs. Among these regulators, A20 was strongly up-regulated at the mRNA and protein levels upon LH2171 treatment. The cell wall fraction of LH2171 also demonstrated a similar increase in A20 gene expression and exerted an anti-inflammatory effect. These results suggest that the cell wall may be one of the anti-inflammatory components of LH2171. Since cell wall components of Gram-positive bacteria are recognized by toll-like receptor 2 (TLR2), we investigated whether the anti-inflammatory effect of LH2171 was mediated by TLR2 signaling. Specifically, LH2171-mediated IL-6 suppression and A20 upregulation in wild-type macrophages were reversed and significantly reduced in TLR2 knock-out macrophages. These results suggest that LH2171 induces A20 expression via TLR2 signaling, inhibiting the activation of NF-κB/MAPKs and cytokine production in antigen-presenting cells. This might contribute to the anti-inflammatory activity of LH2171 on autoimmune diseases.

Probiotics in Extraintestinal Diseases: Current Trends and New Directions

Probiotics are defined as live microorganisms that when administered in adequate amounts confer a health benefit to the host. Their positive supplementation outcomes on several gastrointestinal disorders are well defined. Nevertheless, their actions are not limited to the gut, but may also impart their beneficial effects at distant sites and organs. In this regard, in this review article we: (i) comprehensively describe the main mechanisms of action of probiotics at distant sites, including bones, skin, and brain; (ii) critically present their therapeutic potential against bone, skin, and neuronal diseases (e.g., osteoporosis, non-healing wounds and autoimmune skin illnesses, mood, behavior, memory, and cognitive impairments); (iii) address the current gaps in the preclinical and clinical research; and (iv) indicate new research directions and suggest future investigations.

Lactobacillus helveticus SBT2171 Attenuates Experimental Autoimmune Encephalomyelitis in Mice

We recently reported that Lactobacillus helveticus SBT2171 (LH2171) inhibited the proliferation and inflammatory cytokine production of primary immune cells in vitro, and alleviated collagen-induced arthritis (CIA) in mice, a model of human rheumatoid arthritis (RA). In this study, we newly investigated whether LH2171 could relieve the severity of experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), which is an autoimmune disease, but develop the symptoms by different mechanisms from RA. In MS and EAE, main cause of the disease is the abnormality in CD4⁺ T cell immunity, whereas in RA and CIA, is that in antibody-mediated immunity. The intraperitoneal administration of LH2171 significantly decreased the incidence and clinical score of EAE in mice. LH2171 also reduced the numbers of pathogenic immune cells, especially Th17 cells, in the spinal cord at the peak stage of disease severity. Interestingly, before the onset of EAE, LH2171 administration remarkably decreased the ratio of Th17 cells to CD4⁺ T cells in the inguinal lymph nodes (LNs), where pathogenic immune cells are activated to infiltrate the central nervous system, including the spinal cord. Furthermore, the expression of interleukin (IL)-6, an inflammatory cytokine essential for Th17 differentiation, decreased in the LNs of LH2171-administered mice. Moreover, LH2171 significantly inhibited IL-6 production in vitro from both DC2.4 and RAW264.7 cells, model cell lines of antigen-presenting cells. These findings suggest that LH2171 might down-regulate IL-6 production and the subsequent Th17 differentiation and spinal cord infiltration, consequently alleviating EAE symptoms.