Amelioration and mechanisms of OVA-induced allergic diarrhea by oral administration of the Pediococcus pentosaceus Sn26 strain

Abstract

We investigated the anti-allergic effect of a new strain (Pediococcus pentosaceus Sn26 strain (Sn26 strain)) among 59 strains of lactic acid bacteria isolated from the Japanese traditional fermented vegetable pickle, the 'Sunki pickle'. Oral administration of the Sn26 strain decreased the serum OVA-specific IgE level and ameliorated the appearance of diarrhea in OVA-induced allergic diarrhea mice. A positive relationship was recognized between the serum IgE level and the occurrence of allergic diarrhea. Furthermore, we examined immunological effects of Peyer's patch (PP) cells, splenocytes and lamina propria lymphocytes (LPL) by oral administration of the Sn26 strain. The ability of IL-12 and IFN- productions of PP cells in the Sn26 group were significantly higher than those in the control group, and the total IgE level in the Sn26 group was significantly lower than in the control group. The ability of IL-4 and OVA-specific IgE productions of LPL in the Sn26 group was significantly lower than those in the control group. However, the immune response in splenocytes did not differ between the Sn26 and control groups. These results suggested that the orally administrated Sn26 strain ameliorated allergic diarrhea through improvement of the Th1/Th2 balance in PP cells and subsequent inhibition of IgE production of LPL.