Is it true that mbt sneakers help reduce pain in feet?

Sometimes. They're rocker bottom shoes (convex bottom). In certain cases, the shape of the sole can make up for joints with an otherwise limited range of motion and can make walking more comfortable.
Somewhat. Those shoes have a rocker bottom so it takes pressure off the major pressure points. The downside to the shoes is that you pick up more stress in the forefoot since you are walking more on the ball of your foot. They may make your feet and legs sore when you first begin to wear them.