Completely understood. But the fact of the matter remains that the immune system is a far more intricate and complicated array of cellular networks that involves more than just the nourishment of the gastrointestianl wall. GI immunity is only a single element, not undermining its significance, that constitues one aspect of the human immune system. Cellular and humeral immunity is far more vast and involves the interplay of a sophisticated network of mediators that control our immune status. Immunity even extends far beyond the internal syatem and into the many layers of the human integumentary system. Compromised immunity can manifest in the skin with the explosive proliferation of organisms and inflammatory reactions taking place at the dermal level. Inflammatory mediators may also exhibit this "autoimmune" nature direclty at at the dermal level. Although it's understood that the GI is a prominant system that requires the utmost attention for overall health, it solely cannot be unduely labled as the prime burden-bearer of skin conditions in general. Such a statement would be reckless.
Also, I agree, time is definately needed to yield results. Probiotics in the pill form is also capable of doing the job if its proven to survive GI acids and form CFU's. Fermenting your own cabbage and the like in the kitchen is something I just don't have the time or patience to do .