This document discusses the rise of research on the human microbiome. It provides five reasons for the recent increased interest: 1) increased appreciation of microbial diversity, 2) seeking new areas of research after the human genome was sequenced, 3) advances in DNA sequencing and analysis techniques, 4) understanding the functions of microbes in and on the human body, 5) sequencing costs decreasing drastically. It also outlines some of the major challenges in microbiome research, like complexity from host and environmental factors, and gaining public understanding. Finally, it discusses opportunities in the field, such as improving reference databases, analysis methods, model systems like rice, whole systems approaches, education, citizen science, and more.