As papers just pour out implicating the gut flora in a wide range of diseases the question becomes more and more what to do about it. While pre and probiotics can help, it’s possible that fecal transplants – the direct transfer of stool (or portions of the stool) from a healthy person into the gut of an ill person – may provide a larger, more lasting impact.
http://simmaronresearch.com/2019/08/fecal-transplant-chronic-fatigue-study-promise/