The Bacteria Domain experienced an explosion of novel lineages identified within the last decade, especially of lineages made entirely of uncultured members. Since numerous cultivable bacteria have been shown to be instrumental in human development, health, and diseases, it is reasonable to speculate that strains from uncultured groups, which comprise nearly 80% of the human gut and 68% of human oral microbial consortia, participate in similar functions. The study of human-associated uncultured bacteria, however, has many practical limitations, such as access to patient samples, unpredictable microbial composition, and low relative abundance, all of which challenge experimental promptness and reproducibility. We propose that uncultured bacteria from... |