Ingesting probiotic yogurt containing Lactiplantibacillus plantarum OLL2712 improves glycaemic control in adults with prediabetes in a randomized, double-blind, placebo-controlled trial.

AIM: The ingestion of Lactiplantibacillus plantarum OLL2712 (OLL2712) cells has been shown to improve glucose metabolism by suppressing chronic inflammation in murine models and clinical studies. This study aimed to clarify the effect of OLL2712 on glycaemic control in healthy adults with prediabetes. MATERIALS AND METHODS: The study was a randomized, double-blind, placebo-controlled, parallel-group design. Adult participants with prediabetes [n = 148, glycated haemoglobin (HbA1c) range: 5.6%-6.4%, age range: 20-64 years] were assigned randomly to placebo or OLL2712 groups (n = 74/group) and administered daily for 12 weeks either conventional yogurt or yogurt containing >5 × 109 heat-treated OLL2712 cells, respectively. In addition, the participants were followed for 8 weeks after the discontinuation of either yogurt. The primary outcome was the changes in HbA1c levels at weeks 12 and 16 by analysis of covariance. RESULTS: The levels of HbA1c and glycoalbumin decreased significantly in both groups at week 12 in comparison with those at week 0, but only in the OLL2712 group at week 16. HbA1c levels decreased significantly at weeks 12 and 16 in the OLL2712 group in comparison with the placebo group (p = .014 and p = .006, respectively). No significant inter- and intragroup differences in HbA1c levels were observed at week 20. CONCLUSIONS: The ingestion of OLL2712 prevents the deterioration of glycaemic control and maintains the HbA1c levels within the normal range in adults with prediabetes; yogurt probably exhibits similar effects, which may contribute to reducing the risk of developing type 2 diabetes.

Interleukin-22 enhanced the mucosal barrier and inhibited the invasion of Salmonella enterica in human-induced pluripotent stem cell-derived small intestinal epithelial cells.

Human-induced pluripotent stem cell-derived small intestinal epithelial cell (hiPSC-SIEC) monolayers are useful in vitro models for evaluating the gut mucosal barrier; however, their reactivity to cytokines, which are closely related to the regulation of mucosal barrier function, remains unclear. Interleukin (IL)-22 is a cytokine that contributes to regulate the mucosal barrier in the intestinal epithelia. Using microarray and gene set enrichment analysis, we found that hiPSC-SIEC monolayers activate the immune response and enhance the mucosal barrier in response to IL-22. Moreover, hiPSC-SIEC monolayers induced the gene expression of antimicrobials, including the regenerating islet-derived protein 3 family. Furthermore, IL-22 stimulation upregulated Mucin 2 secretion and gene expression of an enzyme that modifies sugar chains, suggesting alteration of the state of the mucus layer of hiPSC-SIEC monolayers. To evaluate its physiological significance, we measured the protective activity against Salmonella enterica subsp. enterica infection in hiPSC-SIEC monolayers and found that prestimulation with IL-22 reduced the number of viable intracellular bacteria. Collectively, these results suggest that hiPSC-SIEC monolayers enhance the mucosal barrier and inhibit infection by pathogenic bacteria in response to IL-22, as previously reported. These results can contribute to the further application of hiPSC-SIECs in evaluating mucosal barriers.

Yogurt starter strains ameliorate intestinal barrier dysfunction via activating AMPK in Caco-2 cells.

Lactic acid bacteria (LAB) are commonly used probiotics that improve human health in various aspects. We previously reported that yogurt starter strains, Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131, potentially enhance the intestinal epithelial barrier function by inducing the expression of antimicrobial peptides in the small intestine. However, their effects on physical barrier functions remain unknown. In this study, we found that both strains ameliorated the decreased trans-epithelial resistance and the increased permeability of fluorescein isothiocyanate-dextran induced by tumor necrosis factor (TNF)-α and interferon (IFN)-γ in Caco-2 cells. We also demonstrated that LAB prevented a decrease in the expression and disassembly of tight junctions (TJs) induced by TNF-α and IFN-γ. To assess the repair activity of TJs, a calcium switch assay was performed. Both strains were found to promote the reassembly of TJs, and their activity was canceled by the inhibitor of AMP-activated protein kinase (AMPK). Moreover, these strains showed increased AMPK phosphorylation. These observations suggest that the strains ameliorated physical barrier dysfunction via the activation of AMPK. The activities preventing barrier destruction induced by TNF-α and IFN-γ were strain-dependent. Several strains containing L. bulgaricus 2038 and S. thermophilus 1131 significantly suppressed the barrier impairment, and L. bulgaricus 2038 showed the strongest activity among them. Our findings suggest that the intake of L. bulgaricus 2038 and S. thermophilus 1131 is a potential strategy for the prevention and repair of leaky gut.

Lactobacillus paragasseri OLL2809 Improves Premenstrual Psychological Symptoms in Healthy Women: A Randomized, Double-Blind, Placebo-Controlled Study.

Lactobacillus paragasseri OLL2809 has been shown to ameliorate stress. This study employed a randomized, placebo-controlled, double-blind, parallel-group design to assess the efficacy of continuous ingestion of OLL2809 for managing menstrual symptoms in healthy women. Eighty healthy adult women aged 25-40 years who experienced premenstrual and menstrual symptoms were randomly assigned to either the OLL2809 or placebo group (n = 40 each) and ingested tablets containing OLL2809 or placebo for three menstrual cycles. The OLL2809 group exhibited a significantly greater change in premenstrual 'arousal' scores on the menstrual distress questionnaire compared to the placebo group after the three menstrual cycles. Specifically, changes in the 'activity' subfactor were significantly higher in the OLL2809 group than in the placebo group. Additionally, the OLL2809 group reported significantly lower premenstrual irritability on the visual analog scale than the placebo group. These results suggest that OLL2809 may contribute to enhancing the quality of life of women.

Lactiplantibacillus plantarum OLL2712 Induces Autophagy via MYD88 and Strengthens Tight Junction Integrity to Promote the Barrier Function in Intestinal Epithelial Cells.

Autophagy is an important system conserved in eukaryotes that maintains homeostasis by degrading abnormal proteins. Autophagy incompetence in intestinal epithelial cells causes the abnormal function of intestinal stem cells and other cells and damages intestinal barrier function. The disruption of the intestinal barrier causes chronic inflammation throughout the body, followed by impaired glucose and lipid metabolism. Lactiplantibacillus plantarum OLL2712 (OLL2712) is a lactic acid bacterium that induces interleukin-10 production from immune cells, alleviates chronic inflammation, and improves glucose and lipid metabolism. In this study, we hypothesized that OLL2712 exerts anti-inflammatory effects by inducing autophagy and ameliorating intestinal barrier dysfunction, and we investigated its autophagy-inducing activities and functions. Caco-2 cells stimulated with OLL2712 for 24 h showed an increased number of autolysosomes per cell, compared with unstimulated cells. Therefore, the permeability of fluorescein isothiocyanate dextran 4000 (FD-4) was suppressed by inducing autophagy. In contrast, mucin secretion in HT-29-MTX-E12 cells was also increased by OLL2712 but not via autophagy induction. Finally, the signaling pathway involved in autophagy induction by OLL2712 was found to be mediated by myeloid differentiation factor 88 (MYD88). In conclusion, our findings suggest that OLL2712 induces autophagy in intestinal epithelial cells via MYD88, and that mucosal barrier function is strengthened by inducing autophagy.

Orally administered Lactiplantibacillus plantarum OLL2712 decreased intestinal permeability, especially in the ileum: Ingested lactic acid bacteria alleviated obesity-induced inflammation by collaborating with gut microbiota.

Introduction: Chronic inflammation caused by dietary obesity has been considered to induce lifestyle-related diseases and functional ingredients with anti-inflammatory effects are attracting attention. Although multiple studies on obesity had proved the anti-inflammatory effects of ingestion of lactic acid bacteria (LAB) and other functional ingredients on adipose tissue, the precise effects on the intestine, especially on the individual intestinal segments have not been made clear. In this study, we elucidated the mechanisms of Lactiplantibacillus plantarum (basonym: Lactobacillus plantarum) OLL2712 in suppressing obesity-induced inflammation using high fat diet (HFD)-fed mice obesity model. Methods: We orally administered heat-treated LAB to HFD-fed mice model, and investigated the inflammatory changes in adipose tissue and intestinal immune cells. We also analyzed gut microbiota, and evaluated the inflammation and permeability of the duodenum, jejunum, ileum and colon; four intestinal segments differing in gut bacteria composition and immune response. Results: After 3-week LAB administration, the gene expression levels of proinflammatory cytokines were downregulated in adipose tissue, colon, and Peyer's patches (PP)-derived F4/80+ cells. The LAB treatment alleviated obesity-related gut microbiota imbalance. L. plantarum OLL2712 treatment helps maintain intestinal barrier function, especially in the ileum, possibly by preventing ZO-1 and Occludin downregulation. Discussion: Our results suggest that the oral administration of the LAB strain regulated the gut microbiota, suppressed intestinal inflammation, and improved the gut barrier, which could inhibit the products of obesity-induced gut dysbiosis from translocating into the bloodstream and the adipose tissue, through which the LAB finally alleviated the inflammation caused by dietary obesity. Barrier improvement was observed, especially in the ileum, suggesting collaborative modulation of the intestinal immune responses by ingested LAB and microbiota.

Effects of Lactiplantibacillus plantarum OLL2712 on Memory Function in Older Adults with Declining Memory: A Randomized Placebo-Controlled Trial.

The use of probiotics is expected to be an intervention in neurodegenerative conditions that cause dementia owing to their ability to modulate neuroinflammatory responses via the microbiome-gut-brain axis. Therefore, we selected Lactiplantibacillus plantarum OLL2712 (OLL2712), the optimal anti-inflammatory lactic acid bacteria strain with high IL-10-inducing activity in immune cells, and aimed to verify its protective effects on memory function in older adults. A 12-week, randomized, double-blind, placebo-controlled trial was performed with older adults over the age of 65 years with declining memory. The participants consumed either powder containing heat-treated OLL2712 cells or placebo. Memory function was assessed using a computer-assisted cognitive test, Cognitrax. Daily dietary nutrient intake was assessed using the Brief-type Self-administered Diet History Questionnaire (BDHQ). The composition of the gut microbiota was analyzed by fecal DNA extraction and 16S rDNA sequencing. Data from 78 participants who completed the entire procedure were analyzed, and significant improvements in composite memory and visual memory scores were observed in the active group, after accounting for the effect of daily nutritional intake (p = 0.044 and p = 0.021, respectively). In addition, the active group had a lower abundance ratio of Lachnoclostridium, Monoglobus, and Oscillibacter genera, which have been reported to be involved in inflammation. The present study suggests that OLL2712 ingestion has protective effects against memory function decline in older adults.

Ingesting Yogurt Containing Lactobacillus plantarum OLL2712 Reduces Abdominal Fat Accumulation and Chronic Inflammation in Overweight Adults in a Randomized Placebo-Controlled Trial.

BACKGROUND: Chronic inflammation and insulin resistance are factors that are related to obesity. We have suggested that the administration of heat-treated Lactobacillus plantarum OLL2712 (OLL2712) cells can improve glucose and lipid metabolism by suppressing chronic inflammation in mouse models and a preliminary clinical study. OBJECTIVE: The aim of this study was to investigate whether ingesting OLL2712 cells can reduce body fat accumulation and improve metabolic risk factors, in overweight, healthy adults. METHODS: This study was a randomized, double-blind, placebo-controlled, parallel-group trial conducted at a single center in Japan. The study participants included 100 overweight (BMI range, ≥25 to <30 kg/m2) adults aged 20-64 y. They were randomly assigned to either the placebo or OLL2712 group (n = 50 each) and were administered conventional yogurt or yogurt containing >5 × 109 heat-treated OLL2712 cells, respectively, daily for 12 wk. The primary outcome was the 12-wk change in the abdominal fat area, as assessed by computed tomography, and the secondary outcomes were glucose and lipid metabolism-related parameters and chronic inflammation markers, which were analyzed using a linear mixed model. RESULTS: The 12-wk change of abdominal fat area (difference: 8.5 cm2; 95% CI: 0.3, 16.6 cm2; P = 0.040) and fasting plasma glucose (difference: 3.2 mg/dL; 95% CI: 0.8, 5.6 mg/dL; P = 0.021) were significantly less in the OLL2712 group than the placebo group. The overall trend of serum IL-6 was significantly decreased in the OLL2712 group compared with baseline and the placebo group. CONCLUSIONS: The ingestion of heat-treated OLL2712 cells reduces body fat accumulation and the deterioration of glycemic control and chronic inflammation, in overweight, healthy adults. We hypothesize that OLL2712 cells may prevent obesity by regulating chronic inflammation. This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as UMIN000027709.

Total RNA and genomic DNA of Lactobacillus gasseri OLL2809 induce interleukin-12 production in the mouse macrophage cell line J774.1 via toll-like receptors 7 and 9.

BACKGROUND: Lactobacillus gasseri OLL2809 can highly induce interleukin (IL)-12 production in immune cells. Even though beneficial properties of this strain for both humans and animals have been reported, the mechanism by which the bacteria induces the production of IL-12 in immune cells remains elusive. In this study, we investigated the mechanism of induction of IL-12 using a mouse macrophage cell line J774.1. RESULTS: Inhibition of phagocytosis of L. gasseri OLL2809, and myeloid differentiation factor 88 and Toll-like receptors (TLRs) 7 and 9 signalling attenuated IL-12 production in J774.1 cells. Total RNA and genomic DNA of L. gasseri OLL2809, when transferred to the J774.1 cells, also induced IL-12 production. The difference in the IL-12-inducing activity of Lactobacilli is attributed to the susceptibility to phagocytosis, but not to a difference in the total RNA and genomic DNA of each strain. CONCLUSION: We concluded that total RNA and genomic DNA of phagocytosed L. gasseri OLL2809 induce IL-12 production in J774.1 cell via TLRs 7 and 9, and the high IL-12-inducing activity of L. gasseri OLL2809 is due to its greater susceptibility to phagocytosis.

Secretome Analysis of Mouse Dendritic Cells Interacting with a Probiotic Strain of Lactobacillus gasseri.

Probiotics play a key role in the modulation of the gut immune system in health and disease and their action is mediated by molecules exposed on the microorganism surface or secreted probiotic-derived factors. In particular, Lactobacillus gasseri OLL2809, a probiotic microorganism isolated from human feces, has the potential to modulate various immune responses. The dendritic cells (DCs) are considered the main players in orchestrating the immune response, and their contact with intestinal microbiota is crucial for the development and homeostasis of gut immunity. To gain a perspective on the molecular mechanisms involved in the maturation process of DCs and investigate factors that could modulate these processes, a differential proteomic analysis was performed on the secretome of immature DCs, mature DCs (mDCs, induced by lipopolysaccharide (LPS)), and immature DCs challenged with L. gasseri OLL2809 before treatment with LPS (LGmDCs). The maturation process of DCs was associated to profound changes in the protein secretome and probiotic pre-treatment led to a dramatic modulation of several secreted proteins of mDC, not only classical immune mediators (i.e., cytokines, complement factors, T cell Receptor ligands) but also proteins involved in the contractile and desmosome machineries. The latter data highlight a novel mechanism by which L. gasseri can modulate the maturation process of DCs, reinforcing the concept of a protective anti-inflammatory role ascribed to this probiotic strain.

Effects of 12-Week Ingestion of Yogurt Containing Lactobacillus plantarum OLL2712 on Glucose Metabolism and Chronic Inflammation in Prediabetic Adults: A Randomized Placebo-Controlled Trial.

The ingestion of Lactobacillus plantarum OLL2712 (OLL2712) cells improved glucose metabolism by suppressing chronic inflammation in mouse models and in a preliminary clinical study. We aimed to clarify the effect of OLL2712 on glucose metabolism and chronic inflammation for healthy adults. Prediabetic adults (n = 130, age range: 20-64 years) were randomly assigned to either the placebo or OLL2712 groups (n = 65 each) and were administered conventional yogurt or yogurt containing more than 5 × 109 heat-treated OLL2712 cells, respectively, daily for 12 weeks. Reduced HbA1c levels after 12 weeks of treatment were observed in both groups compared to those at baseline; however, the 12-week reduction of HbA1c levels was significantly greater in the OLL2712 group than in the placebo group. Increased chronic inflammation marker levels and insulin-resistant index (HOMA-IR) occurred in the placebo group but not in the OLL2712 group. Fasting blood glucose (FBG) levels did not change significantly in both groups; however, in subgroup analyses including participants with higher FBG levels, FBG levels were significantly reduced only in the OLL2712 group compared to baseline. These results suggest that OLL2712 cell ingestion can reduce HbA1c levels and can prevent the aggravation of chronic inflammation and insulin resistance.

Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 Induce the Expression of the REG3 Family in the Small Intestine of Mice via the Stimulation of Dendritic Cells and Type 3 Innate Lymphoid Cells.

Accumulating evidence clarifies that intestinal barrier function, for example, by the mucus layer, antimicrobial peptides, immune systems, and epithelial tight junctions, plays crucial roles in maintaining our health. We reported previously that yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 induced the gene expression of the regenerating family member 3 (REG3) family, which encodes antimicrobial peptides in the small intestine, although it was unclear how the yogurt activated the intestinal cells related to it. Here, we evaluated the cytokine production from the intestinal immune cells stimulated by these strains in vitro and in vivo to elucidate the mechanism for the induction of the REG3 family by the yogurt. The results showed that stimulation by both strains induced interleukin (IL)-23 production from bone marrow-derived dendritic cells (DCs) and IL-22 production from small intestinal lamina propria (LP) cells. In addition, oral administration of these strains to mice increased IL-23p19+ LPDCs and IL-22+ type 3 innate lymphoid cells and induced the expression of Reg3g in small intestinal tissue. Moreover, we showed that the activities for the induction of IL-23 by DCs were strain dependent on L. bulgaricus and S. thermophilus and that S. thermophilus 1131, which is the predominant species in the yogurt, exhibited relatively higher activity compared to the other strains of S. thermophilus. Our findings suggested that these yogurt starter strains, L. bulgaricus 2038 and S. thermophilus 1131, have the potential to maintain and improve intestinal barrier function by stimulating immune cells in the LP.

Enhancement of Oral Tolerance Induction in DO11.10 Mice by Lactobacillus gasseri OLL2809 via Increase of Effector Regulatory T Cells.

Food allergy is a serious problem for infants and young children. Induction of antigen-specific oral tolerance is one therapeutic strategy. Enhancement of oral tolerance induction by diet is a promising strategy to prevent food allergy in infants. Thus, in this study, we evaluate the effect of probiotic Lactobacillus gasseri OLL2809 (LG2809) on oral tolerance induction in a mouse model. The degree of oral tolerance induction was evaluated by measuring the proliferation and level of IL-2 production of splenic CD4+ T cells from DO11.10 mice fed ovalbumin (OVA) alone or OVA with LG2809. Oral administration of LG2809 significantly decreased the rate of proliferation and IL-2 production by CD4+ T cells from OVA-fed mice. LG2809 increased a ratio of CD4+ T-cell population, producing high levels of IL-10 and having strong suppressive activity. Moreover, LG2809 increased a ratio of plasmacytoid dendritic cells (pDCs) among the lamina propria (LP) in small intestine. When used as antigen presenting cells to naïve CD4+ T cells from DO11.10 mice, LP cells from BALB/c mice fed LG2809 induced higher IL-10 production and stronger suppressive activity than those from non-treated mice. These results suggest that oral administration of LG2809 increases the population of pDCs in the LP, resulting in the enhancement of oral tolerance induction by increasing the ratio of effector regulatory T cells. LG2809 could, therefore, act as a potent immunomodulator to prevent food allergies by promoting oral tolerance.

Modulatory activity of Lactobacillus rhamnosus OLL2838 in a mouse model of intestinal immunopathology.

Gut microbiota and probiotic strains play an important role in oral tolerance by modulating regulatory and effector cell components of the immune system. We have previously described the ability of Lactobacilli to influence both the innate and adaptive immunity to wheat gluten, a food antigen, in mouse. In this study, we further explored the immunomodulatory mechanisms elicited in this model by testing three specific probiotic strains, namely L. rhamnosus OLL2838, B. infantis ATCC15697 and S. thermophilus Sfi39. In vitro analysis showed the all tested strains induced maturation of bone marrow derived dendritic cells (DCs). However, only L. rhamnosus induced appreciable levels of IL-10 and nitric oxide productions, whereas S. thermophilus essentially elicited IL-12 and TNF-α. The anti-inflammatory ability of OLL2838 was then tested in vivo by adopting mice that develop a gluten-specific enteropathy. This model is characterized by villus blunting, crypt hyperplasia, high levels of intestinal IFN-γ, increased cell apoptosis in lamina propria, and reduced intestinal total glutathione (GSHtot) and glutathione S-transferase (GST) activity. We found that, following administration of OLL2838, GSHtot and GST activity were enhanced, whereas caspase-3 activity was reduced. On the contrary, this probiotic strain failed in recovering the normal histology and further increased intestinal IFN-γ. Confocal microscopy revealed the inability of the probiotic strain to appropriately interact with enterocytes of the small intestine and with Peyer's patches in treated mice. In conclusion, these data highlighted the potential of L. rhamnosus OLL2838 to recover specific toxicity parameters induced by gluten in enteropathic mice through mechanisms that involve induction of low levels of reactive oxygen species (ROS).

Differential modulation of innate immunity in vitro by probiotic strains of Lactobacillus gasseri.

BACKGROUND: Probiotics species appear to differentially regulate the intestinal immune response. Moreover, we have shown that different immune-modulatory abilities can be found among probiotic strains belonging to the same species. In this study, we further addressed this issue while studying L. gasseri, a species that induces relevant immune activities in human patients. RESULTS: We determined the ability of two strains of L. gasseri, OLL2809 and L13-Ia, to alter cell surface antigen expression, cytokine production and nuclear erythroid 2-related factor 2 (Nrf2)-mediated cytoprotection in murine bone marrow-derived dendritic cells (DCs) and MODE-K cells, which represent an enterocyte model. Differential effects of L. gasseri strains were observed on the expression of surface markers in mature DCs; nevertheless, both strains dramatically induced production of IL-12, TNF-α and IL-10. Distinctive responses to OLL2809 and L13-Ia were also shown in MODE-K cells by analyzing the expression of MHC II molecules and the secretion of IL-6; however, both L. gasseri strains raised intracellular glutathione. Treatment of immature DCs with culture medium from MODE-K monolayers improved cytoprotection and modified the process of DC maturation by down-regulating the expression of co-stimulatory markers and by altering the cytokine profile. Notably, bacteria-conditioned MODE-K cell medium suppressed the expression of the examined cytokines, whereas cytoprotective defenses were significantly enhanced only in DCs exposed to OLL2809-conditioned medium. These effects were essentially mediated by secreted bacterial metabolites. CONCLUSIONS: We have demonstrated that L. gasseri strains possess distinctive abilities to modulate in vitro DCs and enterocytes. In particular, our results highlight the potential of metabolites secreted by L. gasseri to influence enterocyte-DC crosstalk. Regulation of cellular mechanisms of innate immunity by selected probiotic strains may contribute to the beneficial effects of these bacteria in gut homeostasis.

Effects of Lactobacillus gasseri OLL2809 and α-lactalbumin on university-student athletes: a randomized, double-blind, placebo-controlled clinical trial.

Strenuous exercise reduces immune cell function and increases the risk of respiratory and gastrointestinal infections. In addition, it affects mood state and causes physical fatigue. Athletes require both mental and physical conditioning to execute good performance. In this study, we conducted a randomized, double-blind, placebo-controlled clinical trial to evaluate the immunopotentiation and fatigue-alleviation effects of Lactobacillus gasseri OLL2809 (LG2809) and α-lactalbumin (αLA) in university-student athletes after strenuous exercise. A total of 44 university students who performed strenuous exercise daily were separated into 3 groups to receive a 4-week course of placebo, 100 mg LG2809, or 100 mg LG2809 in combination with 900 mg αLA, respectively. Before and after each dietary treatment, the subjects performed strenuous cycle ergometer exercise for 1 h. Before and after each exercise session, blood samples and visual analogue scale scores for fatigue were obtained. In addition, the mood of each subject before and after the dietary treatment was evaluated using the Profile of Mood States (POMS) questionnaire. LG2809 ingestion was effective in preventing reduced natural killer cell activity due to strenuous exercise and elevating mood from a depressed state. In addition, LG2809 + αLA was found to alleviate minor resting fatigue, which was supported objectively by the significant reduction in the serum reactive oxygen metabolites and transforming growth factor ß1 levels. These effects could be helpful for athletes to maintain mental and physical condition.

Lactobacillus gasseri OLL2809 and its RNA suppress proliferation of CD4(+) T cells through a MyD88-dependent signalling pathway.

Recent studies have shown that probiotics are beneficial in prevention and improvement of inflammatory diseases. Accumulating evidence indicates that probiotics can modulate immune cell responses, although the specific molecular mechanism by which probiotics work remains elusive. Because T cells express receptors for microbial components, we examined whether the probiotic strain Lactobacillus gasseri OLL2809 (LG2809) and its components regulate murine CD4(+) T-cell activation. LG2809, as well as two other Lactobacillus strains, inhibited proliferation of CD4(+) T cells; LG2809 had the strongest suppressive activity among them. RNA isolated from LG2809 was also shown to have suppressive activity. We observed this suppressive effect in the culture of CD4(+) T cells stimulated with anti-CD3/CD28 treatment, suggesting a direct effect on CD4(+) T cells. In contrast, the suppressive effect was not observed for CD4(+) T cells from myeloid differentiation primary response gene 88 (MyD88) protein-deficient mice, and was abrogated in the presence of an anti-oxidant reagent, N-acetyl-cysteine (NAC). These results demonstrate that the suppressive effect of LG2809 and its RNA occurred through a MyD88-dependent signalling pathway and suggest involvement of a reactive oxygen species-dependent mechanism. LG2809 RNA injected subcutaneously suppressed delayed-type-hypersensitivity response in DO11.10 mice, and the suppression was abrogated by treatment with NAC. Collectively, these results suggest that suppression of T-cell proliferation by RNA may be one of the mechanisms when a probiotic bacterial strain exerts suppressive effects on inflammatory responses.

Interleukin-12 inhibits development of ectopic endometriotic tissues in peritoneal cavity via activation of NK cells in a murine endometriosis model.

Involvement of impaired peritoneal immunosurveillance systems has been well established in the pathology of endometriosis. On the other hand, it has been observed that peritoneal administration of IL-12 suppress development of endometriotic lesions in a mouse endometriosis model. We investigated the effect of peritoneal administration of IL-12 on the peritoneal immunosurveillance system regarding NK cells in the mouse model. Treating the endometrial-tissue challenged mice with IL-12 for 5 consecutive days, from day -2 to day 2 (implantation of the endometrial tissues was done on day 0), cytotoxicity of splenic NK cells was enhanced immediately after the administration, on day 3, and development of the endometriotic lesions was reduced on day 21. In vivo NK cell depletion by administration of anti-IL-2Rß mAb resulted in reduction of the cytotoxicity of splenic NK cells concomitant with a significant attenuation of suppressive effect of IL-12 on development of endometriotic lesions. Therefore, it was suggested that IL-12 suppresses development of endometriotic lesions via activation of NK cells, and that NK cells are involved in the primary defense for the development of endometriotic lesions.

Lactobacillus gasseri OLL2809 inhibits development of ectopic endometrial cell in peritoneal cavity via activation of NK cells in a murine endometriosis model.

We have previously reported that peritoneal administration of interleukin-12 (IL-12) suppresses development of ectopic endometriotic lesions via activation of natural killer (NK) cells in a mouse endometriosis model. Lactobacillus gasseri OLL2809 is one of a probiotic lactobacillus that has been selected on an ability to stimulate production of IL-12 from murine splenocytes. In this study, we examined whether the oral administration of heat-killed L. gasseri OLL2809 suppressed development of endometriosis. Administration of L. gasseri OLL2809 for 21 consecutive days resulted in reduction of the development of ectopic endometriotic lesions in an extent similar to IL-12. Although obvious effects of L. gasseri OLL2809 on the peritoneal cytokine levels, population of peritoneal cells as well as cytotoxicity of splenic NK cells, gene expression analysis of the peritoneal cells revealed enhancement in the transcription of IL-2 and natural killer cell triggering receptor 1 genes. Therefore, it was suggested that L. gasseri OLL2809 suppressed development of endometriosis via activation of NK cells.

Lactobacillus gasseri OLL2809 is effective especially on the menstrual pain and dysmenorrhea in endometriosis patients: randomized, double-blind, placebo-controlled study.

In this study, we evaluated the efficacy of Lactobacillus gasseri OLL2809 on endometriosis by the randomized, double-blind and placebo-controlled clinical study, especially against pain, which is one of the causative factors to decrease the quality of life. Sixty-six patients clinically diagnosed with endometriosis were enrolled in this study, 62 of which have successfully completed the trial. The tablets containing 100 mg of L. gasseri OLL2809 (active tablet, n = 29) or placebo tablets (n = 33) were ingested once a day for 12 weeks. Visual analog scale (VAS) of pain intensity at the menstrual period and verbal rating scale (VRS) of dysmenorrhea were significantly improved by the ingestion of the active tablets as compared with placebo tablets. There was no significant change of blood examination and biochemical examination of blood in the enrolled patients. Above results show that the tablet containing L. gasseri OLL2809 is effective on endometriosis, especially against menstrual pain and dysmenorrhea. Moreover, it was found that the tablet has no adverse effects. Therefore, it was suggested that the tablet containing L. gaserri OLL2809 contributes to improve the quality of life in the patients with endometriosis.