"70 percent of your immune system is located in your digestive system, which means that if your gut is overrun with bad bacteria, there’s a good chance your immune system will not be functioning at its best". Dr. Claude Matar
From Mike. Better add your respiration system as well as the un-digested food particles backs up into the respiration system. Skip the "proper" percentages. BOTH are huge and add up to more than anything else including the oft mentioned T cells.
Keep your spine erect by sitting on a chair with a firm seat as you are firmly on top of your sit bones. (You can also use the straw experiment in the Optimal Breathing Kit. Remain relaxed, loosen your belt, sit with your feet flat on the floor in front of you.
ALSO SLOW DOWN SlowFood.com
As you exhale, sense your belly and body relaxing. Do this for at least five minutes before and after each meal. Also, I suggest you get Optimal Digestion and Kombucha that suits your taste.
Our Deepest Calm series of breathing development techniques and exercises may have the most influence on the breathing related digestion than anything else one could do.