Probiotics are well known to be live bacteria or components of bacteria that have a beneficial effect on human health.1) Some probiotics, such as lactic acid bacteria, have been used to improve symptoms resulting from changes in the intestinal flora.2,3) Furthermore, several reports have revealed that these probiotics can act in helping to protect from intestinal infections, 4,5) alter immunostimulation 6) and decrease elevated serum levels of cholesterol 7,8) and glucose 8-10) on several animal models. There have been several recent reports on regulation of allergic antibody production. Intraperitoneal injection of probiotics, heat-killed Lactobacillus casei strain Shirota (LC) 11) and heat-killed Lactobacillus plantarum L-137 12) suppressed antigen-specific immunoglobulin (Ig) E production in a food allergy model in mice. Moreover, the oral feeding of probiotics, heat-killed LC, 13) heat-killed Lactobacillus paracasei KW3110,14) live Lactobacillus acidophilus L92 and Lactobacillus fermentum CP34 15) were effective in inhibiting total IgE production and/or ovalbumin (OVA)-specific IgE production in serum of immunized mice. These reports suggested that the mechanism of the probiotic action might be mediated via the effect of T helper type (Th) 1 cytokine interferon (IFN)-g production through interleukin (IL)-12. [11][12][13][14]16) Bifidobacterium is one of the major intestinal microflora components. During the period when the microflora of the gut becomes established, breast-feeding can promote the intestinal colonization of Bifidobacterium. Recently, He et al. 17) have reported that allergic infants were found to have lower levels of Bifidobacterium bifidum than that of healthy infants.In the present paper, we examined the effect of Bifidobacterium bifidum G9-1 (BBG9-1) on IgE production in OVAimmunized mice and cytokine production of splenocytes from the mice orally administered BBG9-1. MATERIALS AND METHODSBacteria BBG9-1 and Enterococcus faecalis JCM8726 (EFJCM8726) were obtained from our laboratory and the Japan Collection of Microorganisms (Wako, Japan), respectively.BBG9-1 and EFJCM8726 were cultured at 37°C for 20 h in VF broth supplemented with 1% glucose and 0.04% cystine. For in vitro experiments, heat-killed bacteria were obtained by heating the suspension of the bacteria at 100°C for 10 min.For in vivo experiments, BBG9-1 was dried with sodium glutamate and dextrin. These preparations of BBG9-1 contained 2.5ϫ10 11 colony forming units (cfu)/g. Mice Male, 4-week-old BALB/c mice were purchased from Japan SLC (Hamamatsu, Japan). The mice were housed in plastic cages in a room kept at 22Ϯ3°C and 55Ϯ5% humidity, on a 12 h light/dark cycle under pathogen-free conditions. The mice were fed a standard diet (NMF; Oriental Yeast Co., Ltd., Tokyo, Japan) and were allowed free access to water throughout the experimental period.This animal study was approved by the Experimental Animal Care and Use Committee of Biofermin Pharmaceutical Co., Ltd.Oral Administration of Live Bacteria and Immunization (Fig. 1) Live ...

Recent studies of several animal models have shown beneficial effects of probiotics against allergic responses. However, few reports have examined the effects of probiotics on allergic nasal symptoms such as sneezing and nasal obstruction in animal models of allergic rhinitis. This study evaluated the efficacy of Bifidobacterium bifidum G9-1 (BBG9-1) on antigen-induced nasal symptoms using guinea pig models of allergic rhinitis. Oral administration of BBG9-1 significantly inhibited antigen-induced allergic nasal reactions such as sneezing and nasal obstruction. Our results suggest that BBG9-1 may be useful for alleviating nasal symptoms in patients with allergic rhinitis.

Previous studies using experimental animal models have reported the beneficial effects of probiotics on allergic responses; however, their long-term effects on allergic nasal symptoms in clinical settings have not yet been elucidated in detail. In the present study, a guinea pig allergic rhinitis model involving repeated inhalation challenges with a natural allergen, Japanese cedar pollen, was used to examine the longitudinal effects of Bifidobacterium bifidum G9-1 (BBG9-1) on allergic nasal symptoms. BBG9-1 was administered orally once a day. Amelioration of nasal blockage was consistently observed throughout the experimental period in the BBG9-1-treated group. Although challenge-induced sneezing was not significantly inhibited in the BBG9-1-treated group, prolonged treatment with BBG9-1 slightly reduced the frequency of sneezing. Antigen-specific IgE antibody production was also not inhibited in the BBG9-1-treated group. Increases in the numbers of eosinophils and neutrophils in nasal cavity lavage fluid collected after pollen challenge were almost completely suppressed by BBG9-1 treatment, whereas those in mast cell mediators, histamine and cysteinyl leukotrienes were not. In contrast, increases in the levels of nitric oxide metabolites were potently suppressed. Furthermore, prolonged BBG9-1 treatment markedly suppressed exogenous leukotriene D 4 -induced nasal blockage. Thus, prolonged oral administration of BBG9-1 suppresses Japanese cedar pollen-induced allergic nasal symptoms. The inhibitory mechanisms responsible may involve reductions in the responsiveness of target organs, such as endothelial cells in nasal mucosal blood vessels, to chemical mediators.