RESUMEN
OBJECTIVE: Fish-oil enriched diet has a protective effect on experimental animals infected intramuscularly with Klebsiella pneumoniae. It also has beneficial effect in several other diseases, including autoimmune disorders. The pathophysiological effects of dietary fish-oil have still not been revealed although it is expected to influence the immune response. We have previously shown that dietary fish-oil has beneficial effect in mice infected intramuscularly with Klebsiella pneumoniae. If the beneficial effect of dietary fish-oil is due to influence on the immune response it should be independent of the infection site. We therefore investigated whether dietary fish-oil has beneficial effect in intrapulmonary infection with Klebsiella pneumoniae as it has on intramuscular infection with the same bacteria. MATERIALS AND METHODS: Sixty NMRI mice were fed diets enriched with fish-oil (30 mice) or corn-oil (30 mice) for six weeks. The mice were then infected in the lungs with Klebsiella pneumoniae and the survival was monitored. The experiment was performed twice. The results were compared to our earlier results with intramuscular infections. RESULTS: The survival of the mice fed the fish-oil enriched diet and infected in the lungs with Klebsiella pneumoniae was significantly better compared to the survival of mice fed the corn-oil enriched diet in both experiments (p=0.0001 and p=0.0013). These results are similar to our earlier findings when the mice were infected intramuscularly. CONCLUSIONS: These results indicate that the beneficial effect of dietary fish-oil on infection is independent of the site of infection. These results are in accordance with the hypothesis that dietary fish-oil influences the immune response.
