Extracellular vesicle-derived protein from Bifidobacterium longum alleviates food allergy through mast cell suppression

J Allergy Clin Immunol. 2016 Feb;137(2):507-516.e8. doi: 10.1016/j.jaci.2015.08.016. Epub 2015 Oct 1.


Background: The incidence of food allergies has increased dramatically during the last decade. Recently, probiotics have been studied for the prevention and treatment of allergic disease.

Objective: We examined whether Bifidobacterium longum KACC 91563 and Enterococcus faecalis KACC 91532 have the capacity to suppress food allergies.

Methods: B longum KACC 91563 and E faecalis KACC 91532 were administered to BALB/c wild-type mice, in which food allergy was induced by using ovalbumin and alum. Food allergy symptoms and various immune responses were assessed.

Results: B longum KACC 91563, but not E faecalis KACC 91532, alleviated food allergy symptoms. Extracellular vesicles of B longum KACC 91563 bound specifically to mast cells and induced apoptosis without affecting T-cell immune responses. Furthermore, injection of family 5 extracellular solute-binding protein, a main component of extracellular vesicles, into mice markedly reduced the occurrence of diarrhea in a mouse food allergy model.

Conclusion: B longum KACC 91563 induces apoptosis of mast cells specifically and alleviates food allergy symptoms. Accordingly, B longum KACC 91563 and family 5 extracellular solute-binding protein exhibit potential as therapeutic approaches for food allergies.

Keywords: Bifidobacterium longum; Food allergy; extracellular vesicle; family 5 extracellular solute-binding protein; mast cells; ovalbumin; probiotics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / immunology
  • Bacterial Proteins / immunology*
  • Bacterial Proteins / metabolism
  • Bifidobacterium / immunology*
  • Bifidobacterium / metabolism
  • Cell Count
  • Cytokines / biosynthesis
  • Disease Models, Animal
  • Endocytosis / immunology
  • Extracellular Vesicles / immunology*
  • Extracellular Vesicles / metabolism
  • Food Hypersensitivity / immunology*
  • Food Hypersensitivity / metabolism
  • Food Hypersensitivity / microbiology*
  • Immunomodulation*
  • Intestine, Small / immunology
  • Intestine, Small / metabolism
  • Intestine, Small / microbiology
  • Intestine, Small / pathology
  • Mast Cells / immunology*
  • Mast Cells / metabolism
  • Mast Cells / microbiology
  • Mice
  • Probiotics
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism


  • Bacterial Proteins
  • Cytokines