Oral probiotic bacterial administration suppressed allergic responses in an ovalbumin-induced allergy mouse model

This study investigated whether orally administered probiotic bacteria (Bifidobacterium bifidum and Lactobacillus casei) and a gram-negative bacterium (Escherichia coli) function as allergic immune modulators to prevent food allergy, according to the hygiene hypothesis. C3H/HeJ mice were sensitized with ovalbumin (OVA) and cholera toxin for 5 weeks. After sensitization, the OVA-induced mice that were not treated with bacteria had significantly increased levels of OVA-specific IgE, total IgE, and IgG1 in sera, as well as scab-covered tails. In comparison, groups treated with B. bifidum BGN4 (BGN4), L. casei 911 (L. casei), or Escherichia coli MC4100 (E. coli) had decreased levels of OVA-specific IgE, total IgE, and IgG1, and decreased levels of mast cell degranulation and tail scabs. OVA-specific IgA levels were decreased in BGN4- and L. casei-treated groups. In conclusion, administration of E. coli, BGN4, or L. casei decreased the OVA-induced allergy response. However, a normal increase in body weight was inhibited in the E. coli-treated mice and in the montreated mice groups during allergy sensitization. Thus, BGN4 and L. casei appear to be useful probiotic bacteria for the prevention of allergy. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.