The American Gut Project set out to build a comprehensive open-source and open-access microbiome 16S rRNA reference dataset for the scientific community to use. It relies on a crowd-funding model that allows for broad reach across the US population and is set up so that virtually anyone can participate (with the exception of convicted felons and children younger than 6 weeks old). Individuals can elect to receive a collection kit in exchange for a contribution to the project. Though the sample population is not free from bias (being shifted toward older Caucasians interested in their own health), the variability encompassed by the project vastly exceeds that of the HMP [36]. In addition, the project has recently expanded internationally to the UK and Australia to reduce participant overhead for shipping samples (although, to minimize the introduction of technical variability, all samples are extracted at one site, UC San Diego). All participants in the project are consented under protocol #141853 approved by the University of California San Diego’s Human Research Protection Program (HRPP); the protocol specifies that all non-identifying data collected will
