Beneficial effects of heat-treated Enterococcus faecalis FK-23 on high-fat diet-induced hepatic steatosis in mice.

A high-fat diet (HFD) is one of the causes of hepatic steatosis. We previously demonstrated that Enterococcus faecalis FK-23 (FK-23), a type of lactic acid bacteria, exhibits an anti-obesity effect in mice fed a HFD. In the present study, we examined the effects of FK-23 on HFD-induced hepatic steatosis. Male C57BL/6 mice were divided into four groups and given one of four treatments: standard diet (SD); standard diet supplemented with FK-23 (SD+FK); HFD; or HFD supplemented with FK-23 (HFD+FK). For the administration of FK-23, the drinking water was supplemented with FK-23 at a concentration of 2% (w/w). After 11 weeks, histological findings revealed hepatic steatosis in the liver of HFD-fed mice; however, this effect was attenuated by the administration of FK-23. The expression levels of genes involved in fatty acid oxidation in the liver tissue were significantly reduced in the HFD group compared with the SD group, but FK-23 supplementation tended to up-regulate the expression levels of these genes. Our findings show that the inhibitory effect of FK-23 against hepatic steatosis in HFD-fed mice can be explained by the prevention of fat accumulation in the liver through the modulation of the activities of genes involved in hepatic fatty acid oxidation.

Enterococcus faecalis FK-23 affects alveolar-capillary permeability to attenuate leukocyte influx in lung after influenza virus infection.

Infection with influenza A virus, one of the most common life-threatening viruses, causes the accumulation of inflammatory cells in the lung, which is directly correlated with influenza-associated morbidity and mortality. In this study, we investigated the potential of lysozyme-treated Enterococcus faecalis FK-23 (LFK) to prevent influenza in influenza virus-infected mice. C57BL/6N mice were orally administered LFK and intranasally infected with influenza virus A/Puerto Rico/8/34 (H1N1) at lethal doses. After infection with influenza A virus, the survival rate of the LFK-administered mice was significantly higher than that of saline-administered mice. Staining of lung sections with hematoxylin-eosin, and cell counts of lung and bronchoalveolar lavage fluid showed that oral administration of LFK suppressed the excessive infiltration of leukocytes into the lung after viral infection. Extravasation assay revealed that the arrest was mediated by modulation of pulmonary alveolar-capillary permeability. Expression levels of genes involved in matrix degradation, which are correlated with vascular permeability, were downregulated in LFK-administered mice. These findings suggest that stabilizing the integrity of the alveolar-capillary barrier by the administration of LFK improves survival rate.

Effect of water-soluble fraction from lysozyme-treated Enterococcus faecalis FK-23 on mortality caused by influenza A virus in mice.

To maintain homeostasis of the immune system is considered important for the prevention of influenza A virus infection. Aberrant systemic inflammation is frequently induced by influenza A virus infection, and the severity of the symptoms is associated with pathogenicity of the virus. Lactic acid bacteria are known to have a positive effect in maintaining the immune system. Furthermore, preparations of a lactic acid bacteria strain, Enterococcus faecalis FK-23 (FK-23), have been reported to exert preferable homeostatic effects on immune diseases such as allergic rhinitis and early asthmatic responses. In this study, we examined the efficacy of the water-soluble fraction of lysed and heat-treated FK-23 (SLFK) against a lethal influenza A virus challenge. Mice were orally administered SLFK from day -7 to day 20, and intranasally infected with influenza virus A/Puerto Rico/8/34 (H1N1) at 10(3) PFU on day 0. The survival rate of SLFK-administered mice after influenza A virus infection was significantly improved compared with that of control mice. In addition, the mRNA expression level of the anti-inflammatory cytokine interleukin-10 (IL-10) in lung tissues was enhanced by the oral administration of SLFK after influenza A virus infection. These observations suggest that the oral administration of SLFK exerts a protective effect against influenza virus infection through the activation of the anti-inflammatory response.

Enhancement of anti-allergic effects mediated by the Kampo medicine Shoseiryuto (Xiao-Qing-Long-Tang in Chinese) with lysed Enterococcus faecalis FK-23 in mice.

Kampo is a traditional Japanese medicine originating from ancient Chinese medicine which included the administration of herbal prescription, lifestyle advice and acupuncture. Orally administered Kampo prescriptions are believed to be influenced by diet and intestinal microbiota. However, reports on the Kampo administration effects are still limited. Shoseiryuto (TJ-19), which has anti-allergic and anti-inflammatory properties, is a Kampo prescription used clinically for the treatment of allergic bronchial asthma. We examined whether Shoseiryuto administration is affected by a probiotic product, lysed Enterococcus faecalis FK-23 (LFK). BALB/c mice were sensitized with cedar pollen allergen, and the peritoneal accumulation of eosinophils was induced. During a sensitization period of 21 days, varying amounts of Shoseiryuto (and saline as a control) were administered to the mice. The accumulation of eosinophils was significantly reduced by 30 mg/day doses of Shoseiryuto but not by 3 or 9 mg/day doses. Similarly, 3 mg/day Shoseiryuto, 30 mg/day LFK, 3 mg/day of Shoseiryuto co-administered with 30 mg/day of LFK, and saline control were compared. A significant reduction in the accumulation of eosinophils was observed at 3 mg/day Shoseiryuto co-administered with 30 mg/day of LFK. These results suggest that Shoseiryuto-mediated anti-allergic effects are enhanced by the probiotic (LFK). Although not significant statistically, serum allergen-specific and total IgE levels in the treatment group exposed to the mixed agent (ie. Shoseiryuto and LFK) were generally lower than those receiving either one alone. The results indicate a synergistic effect of a Kampo medicine (Shoseiryuto, Xiao-Qing-Long-Tang in Chinese) and lysed Enterococcus faecalis FK-23 on allergic responses in mice.

[Highly sensitive enzyme-linked immunosorbent assay for the quantification of allergens from Dermatophagoides, DER p 1 and DER f 1].

AIM: In order to specifically quantify the two major Dermatophagoides spp. allergens, Der p 1 and Der f 1, separately, we tried to establish a highly sensitive enzyme-linked immunosorbent assay (ELISA). METHODS: Ninety-six-well ELISA plates were coated with mouse monoclonal antibodies specific against Der p 1 or Der f 1. Allergen samples were incubated in the wells for 2 hours at 37 degrees C. After washing with PBS-T, biotinylated rabbit anti-Der 1 polyclonal antibody was added to the wells. The allergens were detected using horse radish peroxidase-conjugated streptavidin, an enzyme substrate (TMB/H2O2) and a microplate reader. RESULTS: The working range of both ELISA systems for Der p 1 and Der f 1 was 40-2500 pg/ml. The intra- and inter-assay coefficients of variation for reproducibility were 0.99-4.38% and 0.68-3.02%, respectively, in Der p 1 ELISA and 1.54-3.65% and 0.39-4.77%, respectively, in Der f 1 ELISA. Moreover, these ELISA systems showed that there was no cross-reactivity between Der p 1 and Der f 1 allergens. CONCLUSION: These ELISA systems may be useful for measuring less than 1 ng/ml of major mite allergens in house dust samples, various pharmaceutical studies such as evaluation of an allergen-inactivating agent, and standardizing recombinant/natural Dermatophagoides spp. allergens.

Effects of Enterococcus sp. isolated from deep seawater on inhibition of allergic responses in mice.

The objective of the present study was to assess the effects of Enterococcus sp. strain TN-3 isolated from deep seawater on inhibition of eosinophil accumulation, IgE production and active cutaneous anaphylaxis (ACA). We investigated the effects of viable and non-viable TN-3 on allergen-induced peritoneal eosinophil accumulation in mice. Viable (5.4 x 1010 colony-forming units per 60 mg) or non-viable TN-3 (60 mg) was orally administered to BALB/c mice that had been sensitised with the cedar pollen (Cryptomeria japonica) allergen. Oral administration of non-viable TN-3 was effective in suppressing eosinophil accumulation while viable TN-3 was ineffective. We also examined the dose-response relationship for non-viable TN-3 in regard to eosinophil accumulation, IgE production and ACA in allergen-primed mice. Non-viable TN-3 was orally administered at doses of 15 mg (low dose), 30 mg (medium dose) and 60 mg (high dose) to BALB/c mice that had been sensitised with cedar pollen allergen. The anti-allergic effects expressed as inhibition of eosinophil accumulation, IgE production and ACA were found at the low and high doses, but not at the medium dose. These results suggest that non-viable TN-3 exhibited anti-allergic effects at doses of 15 and 60 mg.