I assumed that simple sugars count as "refined carbs" and simple sugars are found in lots of stuff including fruits. Btw, my hope is that this very restrictive diet actually isn't necessary for this metabolite.
By definition they aren't refined. You would have to remove the fiber to make those sugars refined as a first step. Fruit isn't pure simple sugars and it certainly doesn't act that way in the gut when buffered with fiber.