Do Probiotics supplements propagate in the gut? I have been speaking to a friend about this. She says probiotic supplements are useless, and you need fibre + RS to get into that ascending colon and a cap full of probiotics hardly makes it through stomach acid to the gut. This is from Natasha Campbell's book as well: "These important foods provide probiotic bacteria in the best possible form. Supplements of probiotics settle in the upper parts of the digestive tract and generally do not make it all the way down to the bowel. Fermented foods will carry probiotic bacteria all the way down to the end of the digestive system. Fermentation predigests the food, making it easy for our digestive systems to handle, that is why fermented dairy products are usually easily digested by autistic children and other people with a damaged gut. Fermentation releases nutrients from the foods, making them more bio-available for the body." From here So is there any research that shows Probiotic supplements (soil based ones) like PA do make it all the way down?