FERMENTED MILKS AND INCREASED ANTIBODY-RESPONSES AGAINST CHOLERA IN MICE

Lactic acid bacteria are known to exert an adjuvant effect either on h umoral or on cellular immune responses and such effects have been desc ribed after parenteral and oral administration of bacteria. However, f ew studies suggest that such effects may be obtained with chronic cons umption of yoghurt. In this experiment, the effects were studied by a fermented milk supplementation on the kinetics of specific antibodies against cholera in Balblc mice. Each mouse was supplemented for 4 x 5 days by gavaging with one of the following diets: milk, yogurt ferment ed by Lactobacillus bulgaricus and Streptococcus thermophilus (strains S.85) (Y); the same product heated for 3min at 70 degrees C (HTFM) or L. casei fermented milk (LcFM, Strain Danone 002). Animals were vacci nated (CH1 + 2 fraction of Vibrio cholerae) during the experiment. Spe cific antibody titres were evaluated by measuring the vibriocidal powe r of the serum from days 32 to 74. The results showed that the animals receiving Y, HTFM and LcFM exhibited kinetics of specific antibody re sponses significantly higher than that observed with the control milk group. The authors were not able to observe any significant difference s for the specific antibody responses between the Y and the HTFM group s. In addition, the total IgG2a levels remained stable in all groups. These results support the idea that, when administered orally, ferment ed milks containing lactic bacteria have adjuvant properties and stimu late the systemic immune system.