The bacterium responsible for helping the body synthesize vitamins And you all know it: E. coli☝🏻 Most of its strains are not only harmless, but also good for our bodies. For example, E. coli helps to synthesize vitamin K, a substance that indirectly, through the synthesis of important proteins, takes part in the process of blood clotting. In addition, we can also say that it helps in the synthesis of a number of B vitamins! That's how useful this bacteria is to us, if we forget about its pathogenic strains.