Diferential immunomodulatory activity of Lactobacillus casei strains isolated from goat milk: impact on intestinal and respiratory infections

SUSANA SALVA; JULIO VILLENA; SUSANA ALVAREZ

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

ELSEVIER SCIENCE BV

Año: 2010 vol. 141 p. 82 - 89

0168-1605

The immune stimulation induced by Lactobacillus rhamnosus CRL1505 (Lr05) and L. rhamnosus CRL1506 (Lr06) on the resistance to infection with an intestinal pathogen (Salmonella typhimurium) and a respiratory pathogen (Streptococcus pneumoniae) was studied in swiss-albine mice experimental models. The cytokine pro␣les that induced the innate and speci␣c immune response in both infectious processes were investigated. Both strains were able to improve resistance against the intestinal pathogen. Only Lr05 was able to induce a signi␣cant decrease in the number of S. pneumoniae in the lung, prevent its dissemination intothebloodandinduceasigni␣cantincreaseinTh1(INF- )andTh2(IL-6,IL-4andIL-10)cytokinelevels in the bronchoalveolar lavages (BAL). The changes in the cytokines pro␣les in BAL were associated with an increase in the number and activity of phagocytic cells and with the increase in speci␣c antibodies in serum and BAL, which would explain the increased resistance to the challenge. The administration of Lr06 did not induce signi␣cant effects at the respiratory mucosal level. The results described in the present paper showed that certain LAB strains can share certain functional properties, although some of them can perform a functional role better than others, so that it is important to perform careful studies on speci␣c strains, according to their therapeutic use.