Project Summary – OVERALL We seek to strengthen and enhance the Integrative Center for Environmental Microbiomes and Human Health (ICEMHH). Our center was established in response to the 2016 announcement of the National Microbiome Initiative (NMI). The NMI was conceived through the recognition that humans are both connected to and reliant upon the microbial communities that constitute the Earth’s microbiomes, in the environment as well as the human body. The NIH plays a central role in funding this effort, “with a particular emphasis on multi-ecosystem comparison studies, and investigation into the design of new tools to explore and understand microbiomes” [NIH Human Microbiome Project]. The focus of the ICEMHH is the interface between the microbial environment and human health, and our research includes clinical, biochemistry and landscape ecology studies. The University of Hawaiʻi brings three compelling strengths to microbiome research: the uniquely tractable and environmentally complexed landscape of the Hawaiian Islands, an exceptionally qualified biology faculty, including an integrated cohort of junior microbiome-focused faculty, and a dedication to the diversity of people that live on the Islands. As the most diverse biome on Earth, Hawaiʻi offers the unique opportunity to study the effects of steep, orthogonal, ecological gradients on human health, vis a vis their microbial symbionts, from mountain to sea, and in both urban and rural settings. The proposed projects aim to address how environmental variables influence microbial assembly, and how, in turn, this impacts host and human health. Our research leverages the natural ecological complexity and phylogenetic diversity of our archipelago to understand the interplay between environmental microbiomes and human health within natural settings. Using invertebrate model hosts and clinical research, we disentangle the mechanisms underlying these landscape-level patterns. Our projects build upon the knowledge, infrastructure and resources developed in Phase 1 to grow center renown, sustainability and capacity. Our long-term goal is that ICEMHH serve as a world-class model for linking environmental microbiology with human health sciences. In this way, the Center will provide lasting contributions to the State of Hawaiʻi, and beyond.