Probiotic spectra of lactic acid bacteria (LAB)

Lactic acid bacteria (LAB) and their probio-active cellular substances exer t many beneficial effects in the gastrointestinal tract. LAB prevent adhere nce, establishment, and replication of several enteric mucosal pathogens th rough several antimicrobial mechanisms. LAB also release various enzymes in to the intestinal lumen and exert potential synergistic effects on digestio n and alleviate symptoms of intestinal malabsoption. Consumption of LAB fer mented dairy products with LAB may elicit antitumor effects. These effects are attributed to the inhibition of mutagenic activity; decrease in several enzymes implicated in the generation of carcinogens, mutagens, or tumor-pr omoting agents; suppression of tumors; and the epidemiology correlating die tary regimes and cancer. Specific cellular components in LAB strains seem t o induce strong adjuvant effects including modulation of cell-mediated immu ne responses, activation of reticuloendothelial system, augmentation of cyt okine pathways and regulation of interleukins, and tumor necrosis factors. Oral administration of LAB is well tolerated and proven to he safe in 143 h uman clinical trials and no adverse effects were reported in any of the tot al 7,526 subjects studied during 1961-1998. In an effort to decrease the re liance on synthetic antimicrobials and control the emerging immunocompromis ed host population, the time has come to carefully explore the prophylactic and therapeutic applications of probiotic LAB.