Effects of milk fermented by Lactobacillus helveticus R389 on immune cells associated to mammary glands in normal situation and a breast cancer model.

DE MORENO DE LEBLANC, A; MATAR, C; PERDIGÓN, G

Boston, Massachusetts, USA

Congreso; 12th International Congress of Mucosal Immunology; 2005

Background: Antitumour activity is an effect attributed to probiotics and their fermented products. We studied the effects of milks fermented by Lactobacillus helveticus (Lh) R389 (proteolytic strain) or Lh L89 (non-proteolytic strain), on a murine breast cancer model. Methods: Mice were fed with milk fermented by Lh R389 or L89, during 7 days. Tumour control group received no special feeding. At the day 8th, mice were injected with breast tumour cells in the mammary gland (MG). Four days post-injection, they received cyclically fermented milk (FM). FM control groups received the cyclical feeding without tumour induction. Rate of tumour growth, IgA+, CD4+, CD8+ and cytokines + cells in MG (immunofluorescence) and in tumour isolated cells (immunoperoxidase), were analyzed. Apoptosis was studied in tumour tissues. Results: Both FM delayed the tumour growth. Cytokines + cells in MG and cells isolated from the tumour showed a regulatory response (IL-10 and IL-4 increases) induced by Lh R389, but not with Lh L89 in mice injected with tumour cells, while TNFa, IFNg and IL-6 decreased in mice from both groups, compared to the tumour control. Mice fed with milk fermented by Lh R389 increased IgA+ and CD4+ cells in MG. Mice only fed cyclically with FM did not change the immune cell or cytokine + cell numbers. Tumour from mice fed with milk fermented by Lh R389 increased apoptotic cells. Conclusion: Seven days of cyclical administration of both FM decreased the tumour growth stimulating an antitumour immune response and modulated the relationship between immune and endocrine systems (IL-6 diminution), involved in the estrogen synthesis. However the down regulation by IL-10 or IL-4 and increased apoptosis were only observed with Lh R389. Compounds released during milk fermentation by Lh R389 would be implicated in the immune regulation The immune activation in MG was only demonstrated in the presence of a local pathology such as a breast tumour but not in normal conditions.