Mysterious entity discovered in human mouth and intestines

thực thể - Ảnh 1. — A strange genetic entity, smaller than a virus, without a protein shell and carrying genetic information called an obelisk, has caused scientists to ask again the question: what is life? - Photo: ARTUR PLAWGO/Science

The strange entity, called an obelisk, was first detected in human gut bacterial genomes and reported as a pre-publication in 2024 by a team at Stanford University. However, at that time, the discovery only documented the existence of obelisks in the human gut, so it did not really attract much attention.

It wasn't until recently, when scientists took a deeper look and found obelisks in the mouth, that attention really exploded. This discovery raises the hypothesis that obelisks may be much more common than originally thought, and may have been "living" with us for millions of years without anyone knowing.

Obelisk: A strange creature between a virus and a viroid

Scientists describe obelisks as single-stranded circular RNA fragments, about 1,000 bases long, much smaller than typical viruses. They lack a protective shell, which sets them apart from most viruses.

However, unlike viroids (a previously known form of simple RNA), obelisks contain at least one or two genes capable of encoding proteins. This makes them an intermediate form of "life" that has never been described in modern biology.

Professor Ed Feil, an evolutionary microbiologist at the University of Bath (UK), said: "Obelisks are circular RNA segments that can self-arrange into rod-shaped structures, and have the ability to affect the genetic activity of the host."

Analyzing data from millions of bacterial genomes that live in the human body, the Stanford team found nearly 30,000 different types of obelisks, spread across the globe.

Of these, 7% of human gut bacteria contained obelisks. More than 50% of human oral bacteria were also found to contain obelisks.

Notably, obelisks in different locations on the body have very different gene sequences, indicating high diversity and evolutionary potential.

Researchers believe that obelisks may have lived alongside humans for millions of years without ever being discovered. This is an incredible feat in the era of modern genetic technology.

Are they friends or enemies?

Currently, there is no evidence that obelisks are harmful to human health. However, because they live inside bacteria, scientists are interested in the possibility that obelisks can alter the genetic activity of host bacteria, thereby indirectly affecting human health, such as immunity, digestion, or even inflammatory diseases.

"The more we look, the crazier things we see in the microscopic world ," cell biologist Mark Peifer (University of North Carolina) shared in Science magazine.

In biology, an organism is considered “alive” if it can replicate, evolve, and affect its environment. Viruses have long been a subject of debate because they cannot replicate without a host cell. But obelisks are even simpler, shellless, tiny, and yet carry genes.

This leads to a big question: Could a virus have evolved from an obelisk, or was the obelisk the final degenerate step of a primitive virus?

The Obelisk is a testament to the fact that science is still on the verge of great discoveries . The human body is home to not only thousands of beneficial bacteria, but also to genetic entities that have yet to be identified.

This discovery is not only biologically significant, but also lays the foundation for further research in the fields of medicine, immunology, and even philosophy of biology, where the question "what is life?" needs to be rewritten once again.

Back to topic

MINH HAI

Source: https://tuoitre.vn/phat-hien-thuc-the-bi-an-trong-mieng-va-ruot-nguoi-20250805062210183.htm