Lactobacilli hydrolysis of cows' milk proteins abrogates their humoral immunoreactivity in patients with immune-mediated diseases

The level of humoral immunoreactivity to total cows’ milk proteins (TCMP) in sera of patients suffering from recurrent oral ulcerations, gastrointestinal diseases or haematological malignancies was investigated. TCMP were also hydrolysed with two different species of lactobacilli and dramatic changes in the levels of specific IgG and IgE were found with statistically significant decreases in the levels of specific antibodies in sera from all patient groups. The levels below cut-off values of IgG specific for TCMP hydrolysates were detected in sera from all patients, while values of IgE for hydrolysates obtained with Lactobacillus helveticus BGRA43 and Lactobacillus zeae LMG17315were below cut-off in 85% and 97% of patients, respectively. Competitive ELISA confirmed the specificity of antibodies for immunogenic TCMP epitopes, demonstrating that lactobacilli hydrolyse TCMP by degrading immunogenic epitopes, and could therefore be used in processing of milk proteins to obtain products suitable for patients with altered immune response on TCMP.