This article gives a good summary on how to use grains in the proper fashion. Grains are a very difficult food item for humans to digest. An unhealthy gut cannot tolerate the until healed. A healthy gut needs the grains to be properly prepared.
The heavily processed foods on the market are not going to be properly perpared and will feed the pathogenic flora.
Eat grains if you have no digestive issues. If you do have digestive issues grains may be returned carefully to the diet after “healing and sealing” the intestinal tract.