Well, it's literally seen as a medical revolution. "There is increasing evidence that the microbiome and its output (our interactome) touch many, if not most, pathways that affect health, disease, and aging. It is reasonable to propose that the composition of the microbiome and its activities are involved in most, if not all, of the biological processes that constitute human health and disease, as we proceed through our own life cycle" http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191014/