The microbiome is ubiquitous and plays a vital role in health and the environment. Unraveling the complexities of the environmental microbiome, including air, soil, and aquatic samples, poses a significant challenge. Similarly, the human microbiome, encompassing skin, oral, and gut microbiomes, is crucial for human health and requires thorough investigation. Methods such as metagenomics, metatranscriptomics, and metabolomics are utilized to comprehend these microbiomes. This Methods Collection seeks protocols and original research articles in this field, aiming to explore cutting-edge research that enhances our understanding of microbial communities in health and the environment.