What Is This Unknown Biological Entity Discovered in Abundance in the Human Body?

At the heart of the human microbiome, a team of researchers from Stanford University has recently made a rather surprising discovery: the presence of a class of unprecedented biological entities, which they have named "obelisks". These structures, composed of RNA, bear similarity to viruses but stand out due to their unique genome, formed from small loops of RNA.


The researchers employed a sophisticated approach, analyzing fragments of the human microbiome's genome using a specifically developed program. This study managed to identify nearly 30,000 obelisks, notably present in 7% of intestinal bacteria and half of the human oral bacteria.

These intriguing entities raise numerous questions regarding their role within the human microbial ecosystem. The researchers, among whom notable scientists such as Mark Peifer from the University of North Carolina are included, wonder how these obelisks might influence the delicate balance of the microbiome. Although their size, generally around 1000 nucleotides, excludes them from being classified as conventional viruses, the obelisks exhibit sequences that could encode proteins involved in RNA replication, making them more complex than the typical viroids.

The emergence of this new class of biological entities raises questions about the evolution of viruses. Some scientists, including Simon Roux from the Lawrence Berkeley National Laboratory, suggest that this discovery could help understand whether viruses evolved from simpler structures such as viroids and obelisks, or if these are regressions from more complex organisms.

The impact of this totally unexpected discovery on human health remains a mystery for now. The researchers emphasize that the obelisks do not appear to be mere RNA "plasmids", but still know nothing about their functioning and implications for human health.