The effect of dietary oils on microflora in experimental colitis in mice

Increasing evidence suggests that a high dietary intake of n-3 fatty acids attenuates inflammation in chemically induced colitis, but there is no report the effect of different dietary oils on Citrobacter rodentium-induced colitis. The aim of this study was to determine the effect of fish oil, canola oil, and safflower oil on Citrobacter rodentium-induced colitis in mice. Groups of 9 mice were fed isoenergetic diets varying only in fat composition for three weeks, before and 10 days after Citrobacter rodentium inoculation. The distal colon was assessed for the histopathology score, bacterial count, and host immune response factors. While the bacterial count was similar in all groups, the histopathology score was at minimum level in the fish oil group, followed (in an increasing order) by canola oil, safflower oil, and chow-diet groups. Our results indicate that in the Citrobacter rodentium-induced colitis model, fish oil, the richest source of omega-3 fatty acids, is most effective in attenuating inflammation. Fish oil has no effect on the number of the bacteria.