Breakthroughs in sequencing technology and computational biology have provided the basis for studies of the myriad ways in which microbial communities in and on the human body influence human health and disease. In almost every medical specialty, there is now growing interest in accurate and replicable profiling of the microbiome for use in diagnostic and therapeutic application.           In the January 2020 issue of Clinical Chemistry, which is devoted to topics in molecular diagnostics, Dr. Robert Schlaberg reviews microbiome diagnostics.