Synergistic effects of a dietary mixture containing pre-and probiotics on food allergy symptoms in mice

Background: To support dietary management of severe cow's milk allergic infants, a synbiotic mixture of pre- and probiotics was designed from source materials that are cultured completely cow's milk-free. Objective: The effectiveness of the synbiotic mixture in reducing food allergic symptoms was compared to that of the pre- or probiotic components separately using a model for Hen's egg allergy. Method: Mice were orally sensitized once a week for 5 weeks to ovalbumin (OVA) using cholera toxin as an adjuvant. Nonsensitized mice received cholera toxin in PBS only. To study synergy of the dietary synbiotic components, mice were fed a control diet or a diet enriched either with 1% (w/w) prebiotics (short-chain fructo-, longchain fructo-oligosaccharides [scFOSlcFOS (9:1)], 2% [w/w (2E9 CFU)] Bifidobacterium breve M-16V or the synbiotics containing scFOSlcFOS + B. breve M-16V for 3 weeks starting after the last sensitization. Anaphylactic shock reactions and acute allergic skin responses were measured upon challenge to OVA. Allergen-specific IgE and mMCP-1 were measured in serum. Exvivo cytokine profiles were determined in spleen cell culture supernatants after 5 days using ELISA. Results: A significant decrease on the acute allergic skin response was observed in mice fed the synbiotics compared to mice fed either the scFOSlcFOS or B. Breve M-16V. Moreover, a reduction in the severity of anaphylactic shock symptoms was only observed in the mice fed the synbiotic diet. No synergistic effect of the synbiotics was observed on IgE or mMCP- 1. Ex-vivo re-stimulation of spleen cells showed higher IL-10 and IFNγ production and a tendency towards reduced IL-5 production in mice fed the synbiotic diet compared to sensitized mice fed the control diet. These effects were not observed in mice fed the scFOSlcFOS or the B. breve M-16V alone. Conclusion: A synergistic effect of the synbiotics (scFOSlcFOS + B. breve M-16V) on allergic symptoms was observed in OVA-sensitized mice. This suggests increased benefits of the combination of these pre- and probiotics on allergy-related parameters in humans if these effects translate, which is being tested in ongoing clinical studies. Mechanistic data suggest that a change in Th2/Treg or Th1 ratio is involved.