Oat Fiber together with Potato Fiber is a big part of the Keto Diet and Low-Carb Cooking throughout the whole of Europe.  Oat Fiber is an insoluble fiber, which is subtracted from the hull and contains almost no carbohydrates.  It contains almost no Calories and Fat, giving us a full blast of Fiber.  As long as you are not going to try and make your own fiber from fresh Oats, which I would not suggest, buying and using Bamboo Fiber in Keto Diet is perfectly ok.