Effect of dietary oils on host resistance to fungal infection in psychologically stressed mice

Psychological stress can modulate host defense against invading pathogens. In this study, we investigated the effect of dietary oils on social isolation stress- induced modulation of host resistance to Paracoccidioides brasiliensis. In olive oil-fed mice, 3 weeks of isolation stress resulted in temporarily delayed clearance of this fungus in the liver compared with group- housed mice. By contrast, in soybean oil-fed mice, isolation stress had no significant effect on antifungal activity. The olive oil-fed mice showed greater liver interferon (IFN)-γ and interleukin (IL)-6 production in response to infection as compared with the soybean oil-fed mice. In the olive oil-fed mice, isolation stress led to greater infection-induced IFN-y production in the liver compared with the group-housed animals. These results indicate that the modulatory effects of psychological stress on host resistance to P. brasiliensis can vary depending on dietary fatty acid composition.