Microorganisms are a major part of the Earth’s biological diversity. Although a lot of research has been done on microbial diversity, most of it is fragmented. This book creates the need for a unified text to be published, full of information about microbial diversity from highly reputed and impactful sources. brings a comprehensive understanding of the recent advances in microbial diversity research focused on different bodily systems, such as the gut. also discusses how the application of advanced sequencing technologies is used to reveal previously unseen microbial diversity and show off its function.