Project Plain Jane

Question for all;has anyone read Grain brain,or Brain maker by David Perlmutter,M.D? If yes,what is your opinion? I agree with his theories,as essentially what I have been doing by changing my diet is changing the micro-biome of my gut.Unbelievable that we carry 4 lbs of bacteria around in our stomach and small intestine.Makes total sense that those microbes have a huge say in our health.
Why hasn't science and western medicine approached this? The answer is simple. They cannot own the fix.