EFECTS OF MILK FERMENTED BY Lactobacillue helveticus ON A MURINE BREAST CANCER

A. DE MORENO DE LEBLANC; C. MATAR; N. LEBLANC; C. THÉRIAULT; G. PERDIGON

Montreal, Canada,

Congreso; Probiotics and Health, Application in the third millennium,; 2004

Antitumour activity is one of the health-promoting effects attributed to the lactic acid bacteria and their products of fermentation. Previous studies in mice demonstrated that bioactive compounds released in milk fermented by L. helveticus (Lh) R389 contribute to its immunoenhancing and antitumour properties. The aim of this work was to study the effects of the consumption of milk fermented by Lh R389 or its non-proteolytic variant Lh L89, on a murine breast cancer model. Mice were fed with milk fermented by Lh R389 or L89, during two or seven days. The tumour control group received no special feeding. At the end of the feeding period, the mice were challenged by a subcutaneous injection of tumour cells in the mammary gland. Four days post-injection, they received fermented milk on a cyclical basis. Rate of tumour development, cytokines in serum and in tumour isolated cells were monitored. Seven days of cyclical administration of both bacterial strains delayed or stopped the tumour development. Cytokines in serum demonstrated that Lh R389 modulated the immune response challenged by the tumour. IL-10 and IL-4 were increased while TNFa increased only in the beginning and then its values remained constant in serum. In comparison with the tumour control, all test groups showed a decrease in seric IL-6, a cytokine involved in the estrogen synthesis. In isolated cells, Lh R389 increased the number of TNFa (+) cells in the middle of the experience, but modulated this enhancement in regards to IL-10. In the last sample, both cytokines decreased. This work demonstrates that 7 days of cyclical administration of milk fermented by both strains of Lh diminishes the tumour growth stimulating an antitumour immune response. Compounds released during milk fermentation with Lh R389 would be implicated in the better regulation of the immune response observed with this strain.