A cross-journal collection from Microbiome, Animal Microbiome and Journal of Animal Science and Biotechnology exploring the microbial contribution to animal health. The gut microbiome is closely associated with the health and performance of animals, which receives wide attention from researchers. Studies using meta-omics approaches could help researchers to further understand the functions and roles of animal-associated microbiome. This cross-journal collection welcomes research and review papers in all aspects including but not limited to: 1) Structure and function of gut microbiota and its interplay with the host 3) Microbiome-driven adaption to the environment of domestic and non-domestic animals 4) Application potential of gut microbiome and the mechanism 5) Microbial cultures and their function in the complex eco-system 6) Development and application of bioinformatic tools Submissions are welcomed to Microbiome, Journal of Animal Science and Biotechnology, and Animal Microbiome. Each manuscript will be peer-reviewed as normal and may be suggested to transfer to another journal to ensure it is placed in the most appropriate journal within this collection. Upon publication, all papers will be included in this collection. This collection has been peer reviewed by the Editorial Boards ofJournal of Animal Science and Biotechnology,Microbiome, andAnimal Microbiome. Journal of Animal Science and Biotechnology is a leading open access journal publishing innovative research across agriculture, dairy and animal science.