One of the most revolutionary advances in the biological sciences in recent years has been the realization that microbial communities occupy virtually every environment and have central roles in human health and disease, as well as in the biogeochemical processes that sustain life on our planet. Moving beyond cataloguing the species and genes that are present in these diverse environments, the microbiome field is now focusing on defining the mechanisms underpinning the interactions between microorganisms and their environment. One of the main goals is to elucidate how the composition and functions of the human microbiota influence the initiation and progression of important human diseases, such as diabetes and cancer, with a view towards improving their diagnosis and treatment. Progress in the field has been driven by multi'omic technologies, combined with new computational tools and models to interpret the vast complexity of this fascinating research area.

In this series of articles, Nature Reviews Microbiology explores the latest developments in the study of environmental and host-associated microbiomes, highlighting the tools and methods that are propelling the field forward, the novel mechanistic insights into the composition and functions of these microbial communities, and the complex interplay between the microbiota and its surroundings.

Diverse microorganisms in patches