Microbial transglutaminase alters the immunogenic potential and cross-reactivity of horse and cow milk proteins.

This research examines the potential for reducing the allergenic reactions to horse milk proteins by using microbial transglutaminase to alter their structure. The research also compares the immunoreactivity of horse milk proteins to cow milk proteins, indicating that horse milk may have fewer allergy risks.

Study Objectives and Methodology

• The researchers aimed to test if the allergenic properties, or immunoreactivity, of horse milk proteins can be diminished through polymerization using microbial transglutaminase (TG).
• The effects of TG on both horse and cow milk were analyzed under a multitude of enzyme dose conditions, and the milk was subjected to conditions simulating the digestive process in humans—through treatment with saliva, gastric, and intestinal fluids.
• The reactions were tested both before, during and after this simulated digestion to determine how these changes endured through the process.

Key Findings

• The study found that horse milk has approximately only half the total protein content of cow’s milk, which potentially reduces its allergenic potential.
• The use of 1 U/g of total milk protein of TG significantly changed the immunoreactivity in both cow and horse milk. The effect of the enzyme on immunoreactivity relied both on the enzyme dosage and the type of milk protein.
• As the doses of TG increased, the immunoreactivity of α-casein went up, while the reactivity of β-lactoglobulin went down. This suggests that specific proteins within milk could have differing reactions to the enzyme treatment.
• After full digestion, horse milk exhibited a markedly lower allergenic property, with a 2.4-fold lesser average IgE reactivity and 4.8-fold lower IgG reactivity compared to cow’s milk, suggesting a lower risk of allergic responses.

Conclusion and Implications

• Microbial transglutaminase alters the immunoreactivity of both horse and cow milk proteins in a manner that is dependent on both the quantity of enzyme and the milk protein type.
• The research suggests that diets modified with horse milk proteins could potentially serve as a safe alternative for individuals with cow milk allergies, although further clinical trials are required to confirm these preliminary findings.