We are home to an unimaginable number of microbial organisms whose collective genome, or “microbiome” contains at least one hundred times as many genes as our own genome. And yet, the roles that these indigenous microorganisms play on health and disease remain poorly characterized. This presentation will briefly touch on the molecular and computational methods using 16S ribosomal RNA that allow us to appreciate more than 99.9999% of microorganisms that live upon and within our body that were previously unrecognized using classical culture-dependent methods. Characterizing and understanding the roles that these organisms may play in health and disease may shed new light in diagnostic and treatment of diseases that are previously categorized as “idiopathic” or immune-mediated. Some of the researches done on humans and dolphins and sea lions by an effort led by Dr. David Relman at Stanford University, and on Crohn’s disease by our very own Dr. Kenny Simpson are discussed.