Criteria for infectious disease causation must take microbial interactions into account. Feature article, Science, 15 Jan 2016 behind a paywall, summary: http://science.sciencemag.org/content/351/6270/224 Produced by NIH's Human Genome Research Institute, let's hope the right hand knows what the left hand is doing and NIH's ME/CFS Clinic Study researchers take heed of it in designing their study. Same for NIH ME/CFS grant reviewers and the CDC. Government agencies have used Koch's original Postulates for decades to justify not funding research into common pathogens like herpes viruses, enteroviruses, etc. citing nearly everyone in the population is exposed to them. This article states: ..."microbial community sequencing can be used to differentiate when an infectious agent induces disease in some but not all hosts." Further, it concludes: "The scientific community should consider infectious disease causation in a broader systems biology context in which host genetic variability, health status, past exposure history, and microbial strains and communities are all important." Directly applicable to all future ME/CFS research. Let's hope Dr. Nahle and others are aware of this.