Abstract <p>The aim of this study was to compare the effects of intragastricadministration of saturated and unsaturated fats of plant and animalorigin over 37 days on the severity of myocardial ischemia-reperfusioninjury (IRI) and behavioral responses in rats with systemic inflammation.Concurrently, the mass fraction of fat in the brain and plasma levelsof various cytokines and biologically active substances were evaluated.The effects of fat-carbohydrate diets of different compositionson experimental endpoints were compared with the effects of probiotictherapy. The animals were allocated into seven groups (<i>n</i> = 8 per group): (1) control; (2)chemically induced colitis on day 30 of the experiment + three-dayadministration of antimicrobial drugs; (3) probiotic correctionwith a mixture of probiotic strains <i>Lactobacillusacidophilus</i> and <i>Bifidobacteriumanimalis</i> subsp. <i>lactis</i>,administered during the last 8 days of the experiment; (4) sunfloweroil + sucrose; (5) clarified butter (ghee) + sucrose; (6) dehydrated margarine+ sucrose; (7) rendered pork fat + sucrose. The systemic inflammatoryresponse, induced by chemically induced colitis combined with short-termadministration of antimicrobial drugs, was characterized by an increasein leukocyte count and elevated levels of pro-inflammatory cytokinesin the blood, as well as a decrease in the mass fraction of fatin the brain. These changes reduced myocardial resistance to IRI,but preventive administration of various fat-carbohydrate dietarycompositions did not influence this process. On the other hand,the systemic inflammatory response was accompanied by significantimpairments in conditioned reflex activity, exploratory behavior,and motor coordination, while probiotic therapy and fat-carbohydratediets of different compositions partially corrected these impairments.The most pronounced effect on the selected experimental endpointswas observed with the fat-carbohydrate diet where the fat componentrepresented a hydrogenated vegetable fat.</p>