Masamichi Toba

Oral intake of Lactobacillus pentosus strain b240 accelerates salivary immunoglobulin A secretion in the elderly: A randomized, placebo-controlled, double-blind trial

BackgroundImmunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections. The effect of oral intake of lactic acid bacteria on salivary secretory IgA (SIgA) in the elderly has not been reported. The objective of this study was to demonstrate the acceleration of salivary SIgA secretion by oral intake of Lactobacillus pentosus strain b240 (b240) in the elderly.ResultsA total of 80 healthy elderly individuals were randomly allocated to either an intervention (i.e., b240) or a control (i.e., placebo) group. The elderly individuals in the b240 group were given a sterile water beverage (125 mL) containing heat-killed b240 (4 × 109 cells), while those in the placebo group were given only a sterile water beverage (125 mL); both groups received their respective beverages once daily for 12 weeks. Saliva was collected before initiation of the study and every 2 weeks thereafter. Saliva flow rate and SIgA concentration were determined, and the SIgA secretion rate was calculated. The mean salivary SIgA secretion rate in the b240 group steadily increased until week 4 (exhibiting a 20% elevation relative to that at week 0), and then remained stable until week 12. Changes in SIgA secretion rate over the intervention period were significantly greater in the b240 group than in the placebo group. The treatment groups exhibited no significant differences in adverse events.ConclusionsOral intake of L. pentosus strain b240 for 12 weeks significantly accelerated salivary SIgA secretion, thereby indicating its potential utility in the improvement of mucosal immunity and resistance against infection in the elderly.

Oral administration of heat-killed Lactobacillus pentosus strain b240 augments protection against influenza virus infection in mice.

Host-defense mechanisms against influenza virus (IFV) infection involve both innate and acquired immunities. Among other components, secretory immunoglobulin A (SIgA) in the airway mucosa plays a particularly pivotal role in preventing IFV infection. Among 150 strains of lactic acid bacteria, Lactobacillus pentosus strain b240 (b240) has the highest IgA-inducing potency in mouse Peyers patch cells. We previously reported a practical new finding that oral ingestion of nonviable heat-killed b240 elevates salivary IgA secretion in humans. The present study aimed to determine if nonviable b240 can prevent IFV infection in mice. In a BALB/c mouse model infected with lethal levels of IFV A/PR8/34 (H1N1), oral administration of b240 for 3 weeks by gavage prior to IFV infection significantly prolonged the survival period. For IFV infection at nonlethal levels, the infectious titers of IFV in the lungs 7 days after infection were significantly reduced after similar b240 administration. Both anti-IFV IgA and immunoglobulin G titers in bronchoalveolar lavage fluid and plasma on day 7 were significantly higher in the b240-treated group than the control group. The augmentation of the anti-IFV immune response by b240 application was preliminarily confirmed by the elevated production of IFV-driven T-cell factors during mixed lymphocyte reactions with b240-primed splenocytes. These results suggest that oral nonviable heat-killed b240 intake can facilitate protection against IFV infection.

Inhibition by Apple Polyphenols of ADP-Ribosyltransferase Activity of Cholera Toxin and Toxin-Induced Fluid Accumulation in Mice

The effects of crude polyphenol extracted from immature apples on the enzymatic and biological activities of a cholera toxin (CT) were investigated. When the apple polyphenol extract (APE) was examined for properties to inhibit CT‐catalyzed ADP‐ribosylation of agmatine, it was found that APE inhibited it in a dose‐dependent manner. The concentration of APE to inhibit 50% of the enzymatic activity of CT (15 μg/ml) was approximately 8.7 μg/ml. The APE also diminished CT‐induced fluid accumulation in two diarrhea models for in vivo mice. In the ligated ileum loops, 25 μg of APE significantly inhibited fluid accumulation induced by 500 ng of CT. In a sealed mouse model, even when APE was administered orally 10 min after a toxin injection, fluid accumulation was significantly inhibited at a comparable dosage. Lineweaver‐Burk analysis demonstrated that APE had negative allosteric effects on CT‐catalyzed NAD: agmatine ADP‐ribosyltransferase. We fractionated the APE into four fractions using LH‐20 Sephadex resin. One of the fractions, FAP (fraction from apple polyphenol) 1, which contains non‐catechin polyphenols, did not significantly inhibit the CT‐catalyzed ADP‐ribosylation of agmatine. FAP2, which contains compounds with monomeric, dimeric, and trimeric catechins, inhibited the ADP‐ribosylation only partially, but significantly. FAP3 and FAP4, which consist of highly polymerized catechin compounds, strongly inhibited the ADP‐ribosylation, indicating that the polymerized structure of catechin is responsible for the inhibitory effect that resides in APE. The results suggest that polymerized catechin compounds in APE inhibit the biological and enzymatic activities of CT and can be used in a precautionary and therapeutic manner in the treatment of cholera patients.

Immunoprotective effects of oral intake of heat-killed Lactobacillus pentosus strain b240 in elderly adults: a randomised, double-blind, placebo-controlled trial

Oral intake of Lactobacillus pentosus strain b240 (b240) has been shown to enhance the secretion of salivary secretory IgA in elderly adults. However, its clinical benefits remain to be determined. We tested the hypothesis that b240 exerts a protective effect against the common cold in elderly adults. The design of the present study was a randomised, double-blind, placebo-controlled trial (RCT) with parallel three-group comparison. For this purpose, 300 eligible elderly adults were randomly allocated to one of three groups, namely a placebo, low-dose or high-dose b240 group. Participants in the low-dose and high-dose b240 groups were given tablets containing 2 × 10(9) or 2 × 10(10) cells, respectively, of heat-killed b240, while those in the placebo group were given tablets without b240. Each group consumed their respective tablets once daily for 20 weeks. The common cold was assessed on the basis of a diary. Change in quality of life was evaluated using the SF-36. Of the total participants, 280 completed the 20-week RCT. The accumulated incidence rate of the common cold was 47·3, 34·8 and 29·0 % for the placebo, low-dose b240 and high-dose b240 groups, respectively (P for trend = 0·012). Lower incidence rates were consistently observed throughout the experimental period in the b240 groups (log-rank test, P= 0·034). General health perception, as determined by the SF-36®, dose-dependently increased in the b240 groups ( P <0·025). In conclusion, oral intake of b240 significantly reduced the incidence rate of the common cold in elderly adults, indicating that b240 might be useful in improving resistance against infection through mucosal immunity.

Protective efficacy of orally administered, heat-killed Lactobacillus pentosus b240 against influenza A virus

Influenza A(H1N1)pdm virus caused the first human pandemic of the 21st century. Although various probiotic Lactobacillus species have been shown to have anti-microbial effects against pneumonia-inducing pathogens, the prophylactic efficacy and mechanisms behind their protection remain largely unknown. Here, we evaluated the prophylactic efficacy of heat-killed Lactobacillus pentosus b240 against lethal influenza A(H1N1)pdm virus infection in a mouse model. To further define the protective responses induced by b240, we performed virologic, histopathologic, and transcriptomic analyses on the mouse lungs. Although we did not observe an appreciable effect of b240 on virus growth, cytokine production, or histopathology, gene expressional analysis revealed that oral administration of b240 differentially regulates antiviral gene expression in mouse lungs. Our results unveil the possible mechanisms behind the protection mediated by b240 against influenza virus infection and provide new insights into probiotic therapy.

Lactobacillus pentosus strain b240 suppresses pneumonia induced by Streptococcus pneumoniae in mice

Aims:  Oral administration of probiotics has been known to improve inflammatory responses against infectious diseases. Here, we describe the inhibitory effect of oral intake of heat‐killed Lactobacillus pentosus strain b240 (b240) on pneumococcal pneumonia in a murine experimental model.

Oral Administration of Heat-Killed Lactobacillus plantarum Strain b240 Protected Mice against Salmonella enterica Serovar Typhimurium

The purpose of this study was to investigate the effects of heat-killed Lactobacillus plantarum strain b240 (b240) on systemic infection by Salmonella enterica serovar Typhimurium (S. Typhimurium) and to determine the mechanism by which b240 protects against infection. Mice were administered either b240 or saline orally for 3 weeks, and then inoculated with S. Typhimurium. The mice treated with b240 were significantly protected against S. Typhimurium as compared to those fed saline. Moreover, translocation of S. Typhimurium into each organ tested in the mice that received b240 tended to be less than in the control mice. An important mechanism of protection against infection was demonstrated by the ability of b240 to inhibit both binding by and invasion of S. Typhimurium into cells. These results indicate that nonviable lactic acid bacteria also play important roles in preventing infection by enteric pathogens.

Role of Lactobacillus pentosus Strain b240 and the Toll-Like Receptor 2 Axis in Peyer's Patch Dendritic Cell-Mediated Immunoglobulin A Enhancement

Lactic acid bacteria are well known to possess immune-modulating effects, but the mechanisms underlying their modulation of the gut immune system are not fully understood. Here, we examined the localization of heat-killed Lactobacillus pentosus strain b240 (b240) in intestinal tissues and the effect of b240 on adaptive immune cascades in the gut. Histological analysis showed that b240 co-localized with dendritic cells (DCs) in the subepithelial dome region of Peyers patches (PPs). In a PP cell culture system, b240 promoted the production of immunoglobulin A (IgA), interleukin (IL)-6, IL-10, interferon (IFN)-γ, and tumor necrosis factor, but not IL-4, IL-5, B-cell activating factors, IFN-α, IFN-β, and transforming growth factor-β1. The enhanced IgA production by b240 was attenuated by neutralizing IL-6, a potent IgA-enhancing cytokine. b240 stimulated DCs to produce an elevated amount of IL-6 in a Toll-like receptor (TLR) 2-, but not TLR4- or TLR9-dependent manner. Finally, we demonstrated that TLR2-mediated IL-6 production from PP DCs in response to b240 activated B cells to produce a large amount of IgA in a DC-B cell co-culture system. Our findings open up the possibility that the heat-killed form of Lactobacillus pentosus strain b240 can be used as a TLR2-mediated DC-activating biologic for enhancing IgA production in the intestine.

Safety evaluation of Lactobacillus pentosus strain b240.

Lactobacillus pentosus has a long history of use in cooked and uncooked fermented foods. Viable and heat-killed nonviable preparations of L. pentosus strain b240 were evaluated for short term and subchronic toxicity and genotoxic potential. Dose levels were determined through acute oral toxicity tests with viable (LD(50)>2500 mg/kg) and nonviable (LD(50)>2000 mg/kg) b240. In the short term study, rats received 2500 mg/kg/day (∼1.7×10(11)cfu/kg/day) viable b240 for 28 days. In the subchronic study, rats received 500, 1000 or 2000 mg/kg/day (up to ∼3.0×10(12) cfu equivalents/kg/day) nonviable b240 for 91 days followed by a 28-day recovery. No mortalities occurred. No treatment-related effects were identified for general condition, body weight, food-water consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights, histopathology and gross pathology. Although statistically significant effects were noted for several endpoints in the short term and subchronic studies, none were related to the test materials. The NOAEL for nonviable b240 was 2000 mg/kg/day, the highest dose tested. Additionally, nonviable b240 (≤ 5000 μg/plate) was not mutagenic in Salmonella typhimurium or Escherichia coli tester strains nor did nonviable b240 orally administered to rats at levels ≤ 2000 mg/kg/day for two days, induce a clastogenic response.

The effects of Lactobacillus pentosus strain b240 and appropriate physical training on salivary secretory IgA levels in elderly adults with low physical fitness: a randomized, double-blind, placebo-controlled trial

The purpose of the study was to evaluate the effects of Lactobacillus pentosus strain b240 (b240) intake and appropriate physical training on salivary secretory immunoglobulin A secretion in elderly adults with low physical fitness. Elderly adults with low physical fitness (daily step count below 3,500 steps) were divided into 2 groups: a b240 intake + exercise group (b240 group) and a placebo intake + exercise group (placebo group). Each subject continued intake of b240 or placebo and moderate-intensity resistance exercise for 12 weeks. Before and 4, 8, and 12 weeks after the start of intervention, each subject underwent saliva sampling. Before and after intervention, physical fitness tests and step count were measured. Our results showed that secretory immunoglobulin A secretion in 57 subjects during the b240/placebo intake period was significantly greater in the b240 group than in the placebo group (p<0.05). There were no significant changes in physical fitness tests before and after intervention in the 2 groups. The daily amount of walking increased significantly after intervention in both groups (p<0.05). These results suggest that in elderly adults with low physical activity and fitness, intake of b240 with appropriate physical exercise elevate salivary secretory immunoglobulin A secretion.