The benefits of black teaweight loss to reduce the risk of developing certain types of cancer and prevent Alzheimer's disease has always been attributed to its high content of antioxidants - polyphenols. Green tea extract contains up to 30-40% of water-soluble polyphenols, and only 3-10% of them remain in the black tea obtained as a result of fermentation. The main polyphenols in fresh tea leaves are epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin (epicatechin). In a recent study led by Lee Hu Chenggyuen Lee National University of Singapore Scientists investigated the effect of 31 phenolic compounds isolated from Chinese Yunnan tea on the growth of 28 species of bacteria in the digestive tract, including pathogenic, symbiotic and probiotic (involved in digestion). According to the results obtained, phenolic compounds have an inhibitory effect on the growth of microflora of the gastrointestinal tract. The degree of suppression of vital activity depends on the type of bacteria and the structure of the compound. Most of all, tea polyphenols and their metabolites inhibit pathogenic microorganisms Escherichia coli, Salmonella typhimurium, Clostridium genera and strains of the Bacteroidaceae family. At the same time, the influence exerted by polyphenols on the growth of probiotic bifidobacteria and lactobacilli is minimal. The authors plan to continue work on studying the effect of tea polyphenols on the intestinal microflora and to search for possible ways to use the information obtained to improve human health and prevent diseases. They believe that an important result of their work is the evidence that antioxidants can be prebiotics at the same time, according to FoodNavigator.