Mucosal immunomodulation by the non-bacterial fraction of milk fermented by L. helveticus R389.

VINDEROLA, G.; MATAR, C.; PALACIOS, J.; PERDIGóN, G.

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

Elsevier

Año: 2007 vol. 115 p. 180 - 186

0168-1605

The health promoting effects ascribed to probiotic bacteria and fermented dairy products arise not only from bacteria themselves but also frommetabolites derived from milk fermentation. Exopolysaccharides produced during milk fermentation and peptides derived from major milkproteins, when released during fermentation, are potential modulators of various regulatory processes in the body. The aim of this work was toincrease the knowledge of the previously observed immunomodulating capacity of milk fermented by Lactobacillus helveticus R389 by the studyof the mucosal immunomodulation exerted by the non-bacterial fraction of the milk fermented at a constant pH6 (NBFpH6). The effects on IL-6production by small intestine epithelial cells, the profile of IgA+ and cytokine+ cells (IL-2, IL-6, IL-10, TNF-á and IFN-ã) induced in the gutlamina propria, and the levels of total and specific secretory IgA in the lumen of BALB/c mice that received NBFpH6 for 2, 5 or 7 days wereexamined. There was an increase in the number of IgA+, IL-10+, IL-2+ and IL-6+ cells after all feeding periods. Total S-IgA in the small intestinelumen increased in mice that received NBFpH6 for 2 days. However, no specific antibodies against NBFpH6 were detected. Feeding of NBFpH6for 7 days significantly (Pb0.05) enhanced IL-6 secretion by small intestine epithelial cells. NBFpH6 induced a non-specific mucosal responsethat was down-regulated for protective immunity, enhancing IL-6 production by epithelial cells and IgA production in the small intestine. Theseevents improve the immunological defenses at the intestinal level, increasing host protection against pathologies. Because mucosal immuneresponses induced by certain dietary antigens play a large part in the prevention of gastrointestinal diseases, the oral administration of a mucosaladjuvant such as NBFpH6 may positively affect the milieu of the intestinal lumen. The opportunity exists then to manipulate the constituents ofthe lumen of the intestine through dietary means, thereby enhancing the health condition of the host.