Protective effect of Enterococcus faecalis DAPTO 512 on the intestinal tract and gut mucosa: milk allergy application

The allergenicity of beta-lactoglobulin (beta-Lg) was studied by using Ussing chamber in a murine model of beta-Lg allergy supplemented with hydrolysates obtained after fermentation of milk for 48 h at 37 degrees C with Enterococcus faecalis DAPTO 512, isolated from cow milk and identified by 16S rDNA sequence analysis. Balb/c mice were sensitised intraperitoneally with beta-Lg. Three groups of mice were formed: group 1, composed of naive mice used as control received only NaCl; group 2, positive control composed of mice sensitised intraperitoneally with beta-Lg; group 3, formed by mice which were given hydrolysates of 48 h then sensitised with beta-Lg. After 48 h of fermentation beta-casein and beta-Lg were degraded by E. faecalis DAPTO 512. beta-Lg immunisation was associated with strong IgG and IgE production in case of positive controls and a significant increase in short current circuit (Isc) and high conductance (G) responses were observed. The control and the hydrolysate groups showed a significant decrease in the production of IgG and IgE anti beta-Lg compared to the positive control. The allergenic potential of beta-Lg was markedly reduced in the group that received hydrolysates (Isc and G remained unchanged after intestine challenge with beta-Lg). The histological scrutiny showed villi atrophy, lymphocyte hyperplasia and a significant chorion detachment in the positive control group. In the group administered with hydrolysates of fermented milk, inflammatory signs were lower, the villi were long and thin and lymphocytes were less dense. The results showed that feeding of milk fermented with E. faecalis DAPTO 512 during 18 days prior to beta-Lg allergy induction exerts a protecting effect on the murine intestine and induces a significant decrease in the beta-Lg allergenicity.