Ravel et al. Microbiome 2014, 2:16 http://www.microbiomejournal.com/content/2/1/16 MEETING REPORT Open Access Human microbiome science: vision for the future, Bethesda, MD, July 24 to 26, 2013 Jacques Ravel1*, Martin J Blaser2, Jonathan Braun3, Eric Brown4, Frederic D Bushman5, Eugene B Chang6, Julian Davies7, Kathryn G Dewey8, Timothy Dinan9, Maria Dominguez-Bello2, Susan E Erdman10, B Brett Finlay5, Wendy S Garrett11, Gary B Huffnagle12,13, Curtis Huttenhower14, Janet Jansson15, Ian B Jeffery16, Christian Jobin17,18, Alexander Khoruts19, Heidi H Kong20, Johanna W Lampe21, Ruth E Ley22, Dan R Littman23,24, Sarkis K Mazmanian25, David A Mills26,27, Andrew S Neish28, Elaine Petrof29, David A Relman30,31, Rosamond Rhodes32, Peter J Turnbaugh33, Vincent B Young12,13, Rob Knight34 and Owen White35 Abstract A conference entitled ‘Human microbiome science: Vision for the future’ was organized in Bethesda, MD from July 24 to 26, 2013. The event brought together experts in the field of human microbiome research and aimed at providing a comprehensive overview of the state of microbiome research, but more importantly to identify and discuss gaps, challenges and opportunities in this nascent field. This report summarizes the presentations but also describes what is needed for human microbiome research to move forward and deliver medical translational applications. Introduction with diseases, but more importantly, the functional roles Each of us consists of about 40 trillion human cells [1] microbiota play in health and disease. and about 22,000 human genes [2], but as many as 100 trillion microbial cells [3] (the microbiota) and 2 million Meeting goals and objectives microbial genes [4] (the metagenome). Understanding To understand the current state of human microbiome the microbial side of ourselves may therefore be critic- research, and to identify key areas for progress going for- ally important for understanding human biology, includ- ward, we held a conference in Bethesda, MD from July ing drug responses [5-8], susceptibility to infectious [9] 24 to 26, 2013, entitled ‘Human Microbiome Science: and chronic [10] disease, and perhaps even behavior Vision for the Future’. This conference, which was sup- [11]. Since the inception of the Human Microbiome Pro- ported in part from a grant by NIH to the University of ject (HMP) in 2007 [4,12], the fundamental understand- Maryland School of Medicine, together with corporate ing of the human microbiome has grown at an ever sponsors including Roche, Qiagen, Illumina, Life Tech- accelerating pace [13]. Together, the HMP healthy co- nologies, MoBio, Metabolon, and the BioMed Central hort study [14,15], and the many associated studies, journal Microbiome, sought to provide an overview of which provide more details on methodology, bioinfor- cutting-edge work in NIH-supported microbiome re- matics analyses, and additional cohorts, have led to over search, and to identify obstacles as well as opportunities 350 publications (http://www.ploscollections.org/hmp). for progress in this challenging field of research. The This work has set the stage for rapid advances, some meeting was organized by a trans-NIH working group, with high potential for translational studies, in under- including 28 participants (programme staff) from 14 (of standing the mechanisms governing the similarities and the 27) NIH Institutes, Centers and Offices, together differences in the microbes we share, their association with four scientific advisory members funded by the Hu- man Microbiome Project. The meeting was attended by * Correspondence: [email protected] 269 participants (and an additional 250 with webcast) 1 Institute for Genome Sciences, Department of Microbiology and from academia, national labs, a range of government agen- Immunology, University of Maryland School of Medicine, 801 W. Baltimore Street, Baltimore, MD 21201, USA cies including NIH, Environmental Protection Agency Full list of author information is available at the end of the article (EPA), US Department of Agriculture (USDA), Food and © 2014 Ravel et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Ravel et al. Microbiome 2014, 2:16 Page 2 of 11 http://www.microbiomejournal.com/content/2/1/16 Drug Administration (FDA), US Agency for International gastrointestinal diseases and conditions, to cancer and even Development (USAID), Office of Science and Technology mental illnesses. Dr. Eric Green (Director of National Hu- Policy (OSTP), US Army, National Science Foundation man Genome Research Institute, NHGRI) (Figure 1C) (NSF), and National Aeronautics and Space Administra- followed with a report on the state and the many accom- tion (NASA), and involved 37 speakers from a broad plishments of the HMP. The HMP aimed to survey the range of disciplines including microbiology, immunology, microbiome in humans through taxonomic and metage- medicine, infectious disease, ecology, and computer sci- nomic analyses. He highlighted the central healthy cohort ence. The broad expertise of the organizing committee of volunteers who were intensively sampled, and several and the participants underscores the way in which mi- demonstration projects that focused on diseases at sites crobes pervade the human body and our environment, such as the GI track, the skin or the urogenital track. These and microbiome research may soon pervade the biomed- projects generated over 3.5 Tbp of data and 8 million ical research enterprise. unique microbial genes were catalogued. These datasets Over the course of this 3-day meeting, there were pre- (sequence data, strains, clinical phenotypes, nucleic acid ex- sentations and discussions aimed towards: tracts, and even cell lines) are publicly available through re- positories and coordinated through a Data Analysis and – Recognizing that the study of the human Coordination Center (DACC) hosted at the Institute for microbiome, in disease and in health, is of relevance Genome Sciences at the University of Maryland School of to the missions of all NIH Institutes and Centers; Medicine [13]. Overall, the HMP has led to over 350 peer- – Increasing awareness across all NIH Institutes and reviewed scientific publications. The HMP has supported Centers of gaps, needs, and challenges faced by the the development of new bioinformatics and technological broad microbiome research community to drive tools, which altogether facilitate the study of the human future research and investments; microbiome for the scientific community. Human micro- – Facilitating coordination between the NIH Institutes biome studies’ ethical, legal and social implications (ELSI) and Centers to promote coherent oversight for were also evaluated, mirroring the Human Genome Project. policies and approaches that will maximally benefit Dr. David Relman (Stanford University) (Figure 2A) gave microbiome-related biomedical research; thefirstofthreekeynoteaddresseson‘Diversity, Stability – Identifying areas where common resources or and Resilience of the Human Microbiome,’ highlighting the partnerships would benefit microbiome-related bio- larger role the human microbiome plays in both health and medical research; disease. He presented recent work from his laboratory on – Exploring how NIH and other government funding the profound effects of antibiotics in reshaping the human agencies could collaborate to integrate the microbiome, and on the value of applying (and perhaps de- microbiome into studies of human health and more veloping) ecological theory for understanding these com- broadly into studies of human interactions with plex ecosystems and their contributions to human biology their physical and microbial environment; [16]. In particular, he raised the issue of resilience, an – Fostering understanding of the current state of ecological concept that refers to the amount of disturb- microbiome research, and shaping an overall vision ance that a system can withstand without changing its for future directions of the field over the next 10 self-organizing processes or services [17]. He empha- years. sized the need for better tools to define resilience and evaluate the stability of, and harm to human-associated Overview: the human microbiome project microbial communities. In the first session Dr. Owen White (University of Dr. Rosamond Rhodes (Icahn School of Medicine at Maryland School of Medicine, Baltimore, MD, USA) Mount Sinai, New York) discussed the ethical, legal, and (Figure 1A) set the stage for the conference, noting that social implications surrounding the study of the human the meeting was a unique opportunity for microbiome re- microbiome. In particular, she spoke on issues related to searchers both to reflect on past successes and to define the subject identification from knowledge of microbiome se- direction that the field could take going forward. His intro- quence data - issues that are in so many ways analogous duction was followed by a presentation by Dr. Francis to those faced by scientists studying the human genome Collins (Director of the National Institutes of Health, sequence. These issues impact the way microbiome sci-