A review article in the current issue of the American Journal of Clinical Nutrition details the therapeutic and preventive effects of yogurt and lactic acid bacteria on diseases such as cancer, gastrointestinal disorders, and asthma. Since the immune system is an important factor in all of these diseases, early researchers proposed that lactic acid bacteria had an immunostimulatory effect. This hypothesis was investigated by using mainly animal models and occasionally, human subjects. Although the results of these studies are not conclusive due to improper experimental design and conditions used, they do provide a strong rationale for the hypothesis that increased yogurt/active lactic cultures consumption, particularly in immuno-compromised populations such as the elderly, may enhance the immune response, which would in turn increase resistance to immune-related diseases.
American Journal of Clinical Nutrition, Vol. 71, No. 4, 861-872, April 2000