Immune-modulating properties of horse milk administered to mice sensitized to cow milk.

The aim of this study was to examine immune adaptive changes, the expression of innate biomarkers and variations in intestinal microbiota composition after horse-milk administration in BALB/c mice, which were sensitized intraperitoneally using cow β-lactoglobulin and α-casein with aluminum adjuvant. We measured serum antibody IgE levels and the expression of MCP-1, IL-4, and TNF-α in duodenal samples. Changes in immune cell populations in peripheral blood were quantified using flow cytometry, and intestinal microbiota composition was assessed using real-time PCR. We found that horse-milk administration decreased serum IgE levels in sensitized mice. The groups that received horse milk showed an increased population of regulatory T cells (CD4+Foxp3+). Horse-milk administration decreased the mRNA levels of IL-4 and resulted in higher transcripts of TLR-4 in all treatment groups; however, the levels of MCP-1, TNF-α, and TLR-2 were unaltered. After horse-milk treatment, we observed a positive effect, with increased numbers of intestinal Bifidobacterium spp. We observed immune-modulating properties of horse milk, but future studies should focus on testing horse-milk processing, such as fermentation and destroying most allergenic epitopes to continue research under clinical conditions.