INVESTIGADORES
ALVAREZ Gladis Susana
artículos
Título:
Lactobacillus casei Improves Resistance to Pneumococcal Respiratory Infection in malnourished mice
Autor/es:
VILLENA JULIO; RACEDO SILVIA; AGÜERO GRACIELA; BRU ELENA; MEDINA MARCELA; ALVAREZ SUSANA
Revista:
JOURNAL OF NUTRITION
Editorial:
HighWire Press
Referencias:
Lugar: Pennsylvania; Año: 2005 vol. 135 p. 1462 - 1469
ISSN:
0022-3166
Resumen:
We studied the effect of Lactobacillus casei CRL 431, when used as supplement in a repletion diet, in the resistance to Streptococcus pneumoniae respiratory infection in malnourished mice. Weaned mice were malnourished after they consumed a protein-free diet (PFD) for 21 d. Malnourished mice were fed a balanced conventional diet (BCD) with or without supplemental L. casei for 7, 14 or 21 consecutive days, or with BCD for 7 d with L. casei supplementation on d 6 and d 7 (7dBCD+2dLc). The malnourished control group (MNC) received only PFD while well-nourished control mice (WNC) consumed the BCD ad-libitum. Mice were challenged with S. pneumoniae at the end of each dietary treatment. Lung colonization and bacteremia were significantly greater in MNC than in WNC. Normalization of the immune response occurred in malnourished mice fed the BCD for 21d. L. casei supplementation reduced the time required for a normal response from 21 to 7 days. Mice repleted with 7dBCD+2dLc treatment had a more effective pathogen clearance from blood and significantly lower lung damage than MNC. This treatment improved both the number of leukocytes and neutrophils in blood and bronchoalveolar lavages (BAL) and the bactericidal function of phagocytic cells, to levels that did not differ from those of WNC. In the 7dBCD+2dLc mice; anti-pneumococcal IgA in BAL was higher than in WNC, while anti-pneumococcal IgG in serum and BAL did not differ. This study suggests that the addition of L. casei to the repletion diet has a beneficial effect, since it accelerates the recovery of the innate immune response and improves the specific immune mechanisms against an S. pneumoniae respiratory infection in malnourished mice.