Probiotic fermenting bacteria only work in the upper part of the gut, not in the colon. The anaerobic bacteria that work in the colon must be slowly acquired by persistent eating of diverse veggies to provide diverse polysaccharides and uncooked veggies to provide the bacteria.
I agree and disagree. It’s an excellent point that the bacteria near the stomach are quite different from the bacteria deep in the colon. So you need different sources of each. I don’t know what “probiotic fermenting bacteria” are (I was under the impression that all bacteria “ferment”), but, yeah, bacteria that live on lactose (e.g., in yogurt) are going to be quite different than bacteria that live on more complex sugars that are digested more slowly than lactose and thus pass further into the intestine.
To me, this explains why I like vegetables. I have no trouble avoiding fruit, bread, rice, pasta, and so on, but I hate meals without vegetables. Why? This line of thought suggests it is because they supply complex polysaccharides needed for deep-colon health. As Ayers implies, you wouldn’t need a lot. This line of thought suggests how you or nutrition scientists can decide what fermented foods to eat (some for each part of the digestive system).
I disagree about raw vegetables. Like most people, I don’t like raw vegetables. I like the crunchiness but the taste is too weak. That most people are like me is suggested by the fact that raw vegetables are almost never eaten without dip or dressing (which add fat and flavor) or something done to make them more palatable (e.g., sugar and liquid from tomatoes). If raw vegetables were important, even necessary, for health, the fact that they are hard to eat would make no evolutionary sense.
I do like pickled/fermented vegetables of all sorts, such as kimchi and sauerkraut. I believe they are a far better source of the bacteria you need than raw vegetables (they have far more of the bacteria that grow on raw vegetables than ordinary raw vegetables).