I really like the idea of FMT as a treatment option (fecal transplant). I think if it were in drug form people would be scrambling to try it given the results. As pointed out by @MaximilianKohler , choosing the right donor is very important. We may even require tailor picked donors to help create better balance. The main downside I see is that patients often find excellent short term improvement followed by (about 2 weeks) decline to baseline. This might be overcome by simply repeating the transplant, which will be much easier when the pills become mass produced. However, I came across this study on patients with IBS: https://www.semanticscholar.org/pap...hang/b9741389178e1969ecdf7177bcbb6e9462afde07 It shows that patients with constipation given a probiotic found relief from that probiotic, but that their stool did not show an increase in the amount of probiotic bacteria. In contrast, the control group stools showed an increase in the amount of probiotic bacteria. What this suggests is that healthy bacteria were somehow prevented from forming colonies in the guts of the patients. This made me wonder if we suffer from essentially the same problem, and this is why FMT is often only effective in the short term. Would like to hear people's thoughts on the idea and this study (@Lassesen ?).