I am still a little bit skeptical about microorganisms from the large intestine entering our blood stream. If that were to happen we would have a blood infection. I agree that the molecules, which are many times smaller then the microorganisms, can enter our blood stream through the small opening between the epithelial cells of gut lining. But bacteria in our blood just doesn't make sense. Some of these bacteria can cause adverse affects when they trespass outside of the boundaries of the colon.