Longitudinal study of effects of oral dosage of Bifidobacterium bifidum G9‐1 on Japanese cedar pollen‐induced allergic nasal symptoms in guinea pigs

Abstract

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.

Oral administration of Bifidobacterium bifidum G9-1 alleviates rotavirus gastroenteritis through regulation of intestinal homeostasis by inducing mucosal protective factors

“…Bifidobacterium bifidum G9-1 (BBG9-1) was isolated from a healthy person, and its high level of safety is certified by the fact that BBG9-1 has been used as an intestinal drug for several decades. In addition to its anti-flatulent effect, other health promotion effects of BBG9-1, including regulation of allergic reactions[12,13], hypertriglyceridemia and hyperglycemia[14], have been investigated.…”

Effects of a probiotic treatment (Enterococcus faecalis) and open-label placebo on symptoms of allergic rhinitis: study protocol for a randomised controlled trial

“…Similar effects have been found for a mixture of bifidobacteria treatment in children with seasonal allergic rhinitis and asthma 55. In addition, animal studies found effects of probiotic treatments on pollen-induced allergic nasal symptoms 56. Nevertheless, the effects of probiotics on allergic rhinitis are still not clear and often inconsistent (in particular when the disease is already established) 12–16…”

Probiotics against airway allergy: host factors to consider

“…Such animal studies can provide crucial insight into the microbe-host interactions that could not be obtained in clinical trials ( Martín et al, 2017 ). Studies on the associations between probiotics, the microbiome and immune-related studies can include other mammalian models, such as guinea pigs ( Tsunemine et al, 2015 ), pigs ( Thomas et al, 2011 ), dogs ( Marsella et al, 2013 ) and macaques ( Hirao et al, 2014 ). However, these nonmurine models are beyond the scope of this Review.…”