@ymedan - Seems to be a variation of the parabiosis concept only with youthful fecal matter-associated microbes, instead of blood factors. Definitely an intriguing prospect; we still need to identify the specific bacterial causal agent(s). This would help in developing a Theory of Aging, but also, by isolating the therapeutic components (protein products?) of the respective commensal bacteria (e.g., species of Bacteroides, Bifidobacter, Lactibacillus, etc.) we can better target pathological conditions, and possibly formulate a ‘biologic’ or pharmacotherapeutic (sans *fecal *transplanting, which is an inexact/imprecise procedure).