Purpose of this article is to clarify the role of intestinal microbiota changes in cardiovascular diseases pathogenesis. In the analysis of intestinal microbiota changes in patients with cardiac pathology, a diversity and lack of research on this issue are notable. Intestinal microflora performs immune, metabolic, synthetic, enzymatic, antitoxic and other functions, providing intestinal colonization resistance. The intestinal microbiota effects on the human body are primarily due to toxic metabolites which can be provisionally divided into five groups: trimethylamine and its derivatives, short-chain fatty acids, endotoxin and bacterial wall products, bile acids and uremic toxins. It is interesting to further study their role in the pathogenesis of heart diseases. For example, bacterial role in trimethylamine, choline metabolism and their effects on the pathogenesis of atherosclerosis. The possibilities of their use as diagnostic markers are studied. However, studies of trimethylamines are usually associated with difficulties, due to their strong dependence on the patient's diet. Trimethylamines are the most studied group of intestinal metabolites, although there are still no reliable ways to correct them. Analysis of short-chain fatty acids requires the identification of each fatty acid individual role, and comparing their content in peripheral blood and stool. Endotoxin is a marker of microbial activity in the intestine. It is an important component of the bacterial cell wall. A study of bile acids metabolism changes influenced by intestinal microbiota also can help to understand disorders of lipid metabolism. An increase in the intestinal microflora uremic toxins (p-cresol, indoxyl sulfate) synthesis is associated with chronic kidney disease. It is promising to develop further ways for correction of the intestinal microbiota composition, which requires a better understanding of cardio-vascular pathology pathogenetic mechanisms.Conclusions. The study of intestinal microbiota composition is appropriate taking into account synthetic activity of various bacteria. Reviewing the effect of microbial metabolites on the human body and studying the mechanisms of their synthesis, it is possible to understand their role as diagnostic markers and suggest ways of correction.