Dr. Natasha Campbell-McBride explains:
"Fermented foods are essential to introduce, as they provide probiotic microbes in the best possible form … fermented foods will carry probiotic microbes all away 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 foods are easily digested by people with damaged gut. Fermentation releases nutrients from the food, making them more bio-available for the body: for example sauerkraut contains 20 times more bio-available vitamin C than fresh cabbage."
On Dr. Campbell-McBride's web site you can find recipes for many traditionally fermented foods, including sauerkraut, yogurt, kefir, kvass and more.