1
Introduction
The 21st century has witnessed a complete revolution in the understanding and description of bacteria in ecosystems and microbial assemblages, and how they are regulated by complex interactions among microbes, hosts, and environments. The human organism is no longer considered a monolithic assembly of tissues, but is instead a true ecosystem composed of human cells, bacteria, fungi, algae, and viruses. As such, humans are not unlike other complex ecosystems containing microbial assemblages observed in the marine and earth environments. They all share a basic functional principle: Chemical communication is the universal language that allows such groups to properly function together. These chemical networks regulate interactions like metabolic exchange, antibiosis and symbiosis (i.e., antagonistic versus advantageous associations), and communication.
The National Academies of Sciences, Engineering, and Medicine’s Chemical Sciences Roundtable organized a series of four seminars in the autumn of 2016 to explore the current advances, opportunities, and challenges toward unveiling this “chemical dark matter” and its role in the regulation and function of different ecosystems. The first three focused on specific ecosystems—earth, marine, and human—and the last on all microbiome systems. In the Earth Seminar, Professors Kelly C. Wrighton (The Ohio State University), William P. Inskeep (Montana State University), and Trent R. Northen (University of California, Berkeley) highlighted the role of chemical communication in the function and regulation of geosystems. In the Marine Seminar, Professor Mark E. Hay (Georgia Institute of Technology), Dr. Mak A. Saito (Woods Hole Oceanographic Institution), and Dr. Daniel J. Repeta (Woods Hole Oceanographic Institution) described molecular mechanisms that regulate ocean biochemistry. In the Human Microbiome Seminar, Professors Pieter C. Dorrestein (University of California, San Diego), Curtis Huttenhower (Harvard University), and Emily P. Balskus (Harvard University) described the current knowledge, technical advances, and challenges faced in revealing the chemical communication of health and disease in the human ecosystem. In the last seminar, on all systems, Professors Timothy K. Lu (Massachusetts Institute of Technology), Mohammad R. Seyedsayamdost (Princeton University), and Jennifer L. Reed (University of Wisconsin–Madison) highlighted the fundamental mechanisms of host–environment–microbial communities’ interactions, and how new technologies and approaches are contributing to their characterizations.
The objective of the series was to highlight the key role of chemistry in these communities’ interplay and to showcase exciting advances that are rapidly evolving this research field, while building an understanding of the concomitant challenges and areas where knowledge is currently lacking. The hope is that this series will promote the sharing of knowledge, and will lead to the identification of cross-system and cross-platform commonalities and opportunities for collaboration. This would represent an important step in overcoming shared technical challenges while amplifying the impact of the research to all microbiome systems. Ultimately, the goal of the series was to amplify the impact of this research, which has the potential for transformative advances in the chemical sciences.