The microbiota inhabiting the human gastro-intestinal tract is reported to have a significant impact on the health of an individual. Recent findings suggest that the microbial imbalance of the gut may play a role in pathogenesis of cardiovascular diseases (CVD). Therefore, several studies have delved into the aspect of altering gut microbiota with probiotics as an approach to prevent and/or treat CVD. The World Health Organization defines probiotics as live microorganisms that, when consumed in adequate amounts, have a positive influence on the individual's health. The present review focuses on strategies of human dietary intervention with probiotic strains and their impact on cardiovascular risk factors like hypercholesterolemia, hypertension, obesity and type-2 diabetes. Accumulating evidence shows probiotics to lower low density lipoproteins (LDL)-cholesterol and improve the LDL/high density lipoproteins (HDL) ratio, as well as lower blood pressure, inflammatory mediators, blood glucose levels and body mass index. Thus, probiotics have the scope to be developed as dietary supplements with potential cardiovascular health benefits. However, there is not only ambiguity regarding the exact strains and dosages of the probiotics that will bring about positive health effects, but also factors like immunity and genetics of the individual that might influence the efficacy of probiotics. Therefore, further studies are required not only to understand the mechanisms by which probiotics may beneficially affect the cardiovascular system, but also to rule out any of their probable negative effects on health. The present review aims to critically appraise the complexity of the available data with regard to the cardiovascular benefits of probiotics.

In this mini-review several commonly used animal models of atherosclerosis have been discussed. Among them, emphasis has been made on mice, rabbits, pigs and non-human primates. Although these animal models have played a significant role in our understanding of induction of atherosclerotic lesions, we still lack a reliable animal model for regression of the disease. Researchers have reported several genetically modified and transgenic animal models that replicate human atherosclerosis, however each of current animal models have some limitations. Among these animal models, the apolipoprotein (apo) E-knockout (KO) mice have been used extensively because they develop spontaneous atherosclerosis. Furthermore, atherosclerotic lesions developed in this model depending on experimental design may resemble humans' stable and unstable atherosclerotic lesions. This mouse model of hypercholesterolemia and atherosclerosis has been also used to investigate the impact of oxidative stress and inflammation on atherogenesis. Low density lipoprotein (LDL)-r-KO mice are a model of human familial hypercholesterolemia. However, unlike apo E-KO mice, the LDL-r-KO mice do not develop spontaneous atherosclerosis. Both apo E-KO and LDL-r-KO mice have been employed to generate other relevant mouse models of cardiovascular disease through breeding strategies. In addition to mice, rabbits have been used extensively particularly to understand the mechanisms of cholesterol-induced atherosclerosis. The present review paper details the characteristics of animal models that are used in atherosclerosis research.