Background. High gut microflora quality plays a crucial role in cardiovascular protection and undisturbed liver function. Currently, the most effective methods to ameliorate gut microbiota influence on the host’scardiovascular health state are investigated. Next to low low-density lipoprotein (LDL) and low non-high-density lipoprotein (non-HDL) serum levels, triglycerides (TG) seem to be a new goal of cardioprotectivetreatment and prevention. Moreover, it has been documented that high serum alanine transaminase (ALT)is a reliable marker of cardiovascular risk. Probiotics are a well proven factor decreasing blood LDL andtotal cholesterol (TCH) concentrations. However, the effect of probiotics on serum TG and ALT levels remainsunderinvestigated. The aim of the study was to compare the effect of 6-week-long supplementationwith a multispecies probiotic mixture in two doses on body mass, liver function and lipid profile in therat model.Material and methods. Thirty ‘Wistar’ rats were randomly divided into the control group – KK, a groupreceiving a probiotic in a daily dose of 2.5×109 CFU (PA) and a group receiving a probiotic in a daily doseof 1×1010 CFU (PB) for 6 weeks. After 6 weeks body mass, liver mass, serum concentrations of TCH, LDL,high-density lipoprotein (HDL), TG, ALT and aspartate transaminase (AST) were determined.Results. Neither at baseline nor at the end of the experiment were there any differences in the body massof rats between all three groups. At the completion of the study the liver mass of the rats was significantlylower in the PA and PB vs. KK group. In group PB a significantly lower serum concentration of TG and ALTcompared to the KK group was registered at the end of the trial.Conclusion. Six-week-long supplementation with multispecies probiotic mixture exerts a favorable anddose-dependent effect on liver function and lipid profile in the rat model and may also have a favorable influenceon cardiovascular impairments. Thus, the inclusion of probiotics supplementation in cardiovascular riskmanagement should be considered © Copyright by 2016. Wydawnictwo Uniwersytetu Przyrodniczego w Poznaniu