Lactobacillus gasseri SBT2055 Enhances Oral Tolerance in Mice via Breastfeeding

Summary : Maternal administration of probiotics is known to be effective for prevention of allergic symptoms in babies by suppressing the immune reaction to orally ingested proteins （ oral tolerance ） . We investigated whether breast milk nourishment by mother mice that had been orally administrated Lactobacillus gasseri SBT 2055 （ LG 2055） with food antigen contributed to allergy prevention in their pups. Female BALB/c mice （ dams ） were fed a diet containing casein （ C group ） , egg white （ E group ） , or egg white with LG 2055 （ E ＋ LG group ） . After induction of pregnancy, pups fed on their dam ʼ s milk were systemically immunized with ovalbu-min （ OVA ） . Then, at the age of seven weeks, the pups were given an intragastric OVA challenge. The incidence of diarrhea was significantly suppressed in pups of the E ＋ LG group relative to the E group. Moreover, the amounts of total IgA and OVA-specific IgA immune complex （ IgA-IC ） in the breast milk were significantly in-creased by administration of LG 2055 . These findings suggest that the increase of IgA-IC in breast milk by LG 2055 might closely correlate with enhancement of oral tolerance in pups.