[Dietary fish-oil supplementation increases survival in mice following Klebsiella pneumoniae infection.].
BACKGROUND
Epidemiological studies have shown that high intake of omega-3 fatty acids correlates with low incidence of various diseases such as cardiovascular diseases, asthma, diabetes mellitus and various auto-immune disorders. It may therefore be suggested that omega-3 fatty acids have substantial impact on the immune system. Studies of the effect of omega-3 fatty acids on survival in bacterial infections have however been contradicting. A Dutch study from 1991 showed increased survival in mice fed fish-oil following infection with Klebsiella pneumoniae. Because of the contradicting results the authors conducted a study with the hypothesis that fish-oil intake increases survival after severe Klebsiella pneumoniae infection.


METHODS
Thirty mice were fed fish-oil enriched diet (10%), olive-oil enriched diet (10%) or standard chow diet. After six weeks the mice were injected intramuscularly with l.óxlO2 cfu of Klebsiella pneumoniae. The survival was measured at regular time intervals for 120 hours.


RESULTS
After 56 hours, 93% of the mice fed fish-oil were alive and 68% and 40% of the mice fed olive-oil and standard chow respectively. The overall survival after 120 hours was 40% in the fish-oil group, 25% in the olive-oil group and 20% in the standard group. The survival after 120 hours of the mice fed the fish-oil enriched diet was significantly better when compared to the two other groups (p=0.0034).


CONCLUSIONS
We conclude that fish-oil enriched diet increases survival of NMRI mice following infection with Klebsiella pneumoniae when compared to olive-oil supplementation or standard chaw. We therefore conclude that the difference in survival is probably based on the effect of omega-3 fatty acid on the immune system. The immunological pathway is still unknown and our results encourage further studies.
Bjornsson
S
S
Hardardottir
I
I
Gunnarsson
E
E
Haraldsson
A
A