Fiber is very important and it was a huge part of ancient diets, that's why cancer and heart disease was almost non-existent in the old days. Fiber removes toxins and bad cholesterol from the body, helps with digestion and feeds gut bacteria. I know that fermented dairy is great for gut bacteria too, but that doesn't mean you should skimp on fiber. Majority of people in the western world are not deficient on protein but they are seriously deficient in fiber.